Copyright © 2020 Betsy J. Grey.
 See Robin West, Women in the Legal Academy: A Brief History of Feminist Legal Theory, 87 Fordham L. Rev. 977, 982 (2018) (stating that Ruth Bader Ginsburg was “winning lawsuits that would establish gender as something akin to a suspect class . . . and would soon render all gender distinctions in federal and state law presumptively unconstitutional”).
 See Daphna Joel & Cordelia Fine, Opinion, Can We Finally Stop Talking About ‘Male’ and ‘Female’ Brains?, N.Y. Times (Dec. 3, 2018), https://www.nytimes.com/2018/12/03/opinion/male-female-brains-mosaic.html [https://perma.cc/JKQ4-6ANV]. The Barnard Center for Research on Women devoted an entire issue to this research. See generally Rebecca Jordan-Young, Giordana Grossi & Gina Rippon, Introduction: Fifty Shades of Grey Matter, Scholar & Feminist Online: Neurogenderings (2019), http://sfonline.barnard.edu/neurogenderings/introduction-fifty-shades-of-grey-matter [https://perma.cc/J6HW-FQPN] (introducing a series of articles on scientific issues about sex, gender, and brains); Gina Rippon, The Gendered Brain (2019) (discussing the history of sex-difference research); see also Larry Cahill, Denying the Neuroscience of Sex Differences, Quillette (Mar. 29, 2019) [hereinafter Cahill, Denying the Neuroscience], https://quillette.com/2019/03/29/denying-the-neuroscience-of-sex-differences [https://perma.cc/8FTQ-PVYV] (introducing the scientific debate on sex differences in brains and arguing that differences do exist).
 See Cahill, Denying the Neuroscience, supra note 2.
 See Joel & Fine, supra note 2.
 This line of research is an outgrowth of the movement toward precision-based therapies. See Claudette Elise Brooks & Janine Austin Clayton, Sex/Gender Influences on the Nervous System: Basic Steps Toward Clinical Progress, 95 J. Neurosci. Rsch. 14, 16 (2017); Jill B. Becker, Michele L. McClellan & Beth Glover Reed, Sex Differences, Gender and Addiction, 95 J. Neurosci. Rsch. 136, 143 (2017). This fundamental shift in research focus is reflected in the themed issue of the Journal of Neuroscience Research, which is devoted entirely to the issue of sex influences on the brain and nervous system functioning. See generally 95 J. Neurosci. Rsch. 1 (2017).
 See Joel & Fine, supra note 2; see also Jordan-Young et al., supra note 2 (noting that feminist language and histories “have been coopted to advance reductive and biologically deterministic claims”).
 Brooks & Clayton, supra note 5, at 14.
 Nat’l Inst. of Health, Consideration of Sex as a Biological Variable in NIH-Funded Research (June 9, 2015), https://grants.nih.gov/grants/guide/notice-files/NOT-OD-15-102.html [https://perma.cc/FQC6-ZX8V]. This policy provoked various objections from the field, including concern for how the policy might strengthen biases based on sex and gender and could disregard feminist considerations on sex and gender in the fields of health and biology. See Nur Zeynep Gungor, Annie Duchesne & Robyn Bluhm, A Conversation Around the Integration of Sex and Gender When Modeling Aspects of Fear, Anxiety, and PTSD in Animals, Scholar & Feminist Online: Neurogenderings (2019), http://sfonline.barnard.edu/neurogenderings/a-conversation-around-the-integration-of-sex-and-gender-when-modeling-aspects-of-fear-anxiety-and-ptsd-in-animals [https://perma.cc/3ACT-J7T4]; Heather Shattuck-Heidorn & Sarah S. Richardson, Sex/Gender and the Biosocial Turn, Scholar & Feminist Online: Neurogenderings (2019), http://sfonline.barnard.edu/neurogenderings/sex-gender-and-the-biosocial-turn [https://perma.cc/SMA4-HLH5] (arguing that to require documentation of sex differences in preclinical research would underplay the effects of gender as a biosocial variable).
 I use the term “sex-based” (or sexually dimorphic) to refer to physical traits of an organism that are indicative of its biological sex and the term “sex-biased” to refer to traits, patterns, or conditions exaggerated in one sex, but that can show varying degrees of overlap. See Franck Mauvais-Jarvis, Arthur P. Arnold & Karen Reue, A Guide for the Design of Pre-Clinical Studies on Sex Differences in Metabolism, 25 Cell Metabolism 1216, 1216 (2017); Margaret M. McCarthy et al., Sex Differences in the Brain: The Not So Inconvenient Truth, 32 J. Neurosci. 2241, 2241–42 (2012).
 See Larry Cahill, Why Sex Matters for Neuroscience, 7 Nature Revs. Neurosci. 477, *1 (2006) [hereinafter Cahill, Why Sex Matters] [https://perma.cc/3ZP6-B5NW]. But see Vanessa Bentley et al., Improving Practices for Investigating Spatial “Stuff”: Part I: Critical Gender Perspectives on Current Research Practices, Scholar & Feminist Online: Neurogenderings (2019), http://sfonline.barnard.edu/neurogenderings/improving-practices-for-investigating-spatial-stuff-part-i-critical-gender-perspectives-on-current-research-practices [https://perma.cc/RRN5-82W9] (challenging findings of sex differences in spatial ability and arguing that gender disparities cannot be explained by biological factors alone).
 As some scholars have noted about this research,
Jordan-Young et al., supra note 2; see also Annelies Kleinherenbrink, Vanessa Bentley & Sigrid Schmitz, Plasticity and Spatial Stuff Under Western Neoliberal Order, Scholar & Feminist Online: Neurogenderings (2019), http://sfonline.barnard.edu/neurogenderings/plasticity-and-spatial-stuff-under-western-neoliberal-order [https://perma.cc/5D9D-BHSR] (arguing that “the brain should certainly be embraced as a valuable source of knowledge,” but also “recognizing the role of contextual factors” that contribute to differences in neurological and behavioral outcomes).
 Research in this area does not support the gross generalization that there are “male” brains and “female” brains or “male” natures and “female” natures. Jordan-Young et al., supra note 2; see Katherine Bryant, Giordana Grossi & Anelis Kaiser, Feminist Interventions on the Sex/Gender Question in Neuroimaging Research, Scholar & Feminist Online: Neurogenderings (2019), http://sfonline.barnard.edu/neurogenderings/feminist-interventions-on-the-sex-gender-question-in-neuroimaging-research [https://perma.cc/J47K-E82K] (noting that the field is “fraught with interpretational problems” and arguing that scientists should eschew dichotomization inherent in sex/gender research). Most scientists agree that “[b]rains and behavior are the product of the combined, continuous interactions of innumerable causal influences, that include, but go well beyond, sex-linked factors.” See Joel & Fine, supra note 2.
 Litigants have begun to introduce neuroscience evidence in various areas of law. See Francis X. Shen, Law and Neuroscience 2.0, 48 Ariz. St. L.J. 1043, 1048–49 (2016).
 A word on vocabulary: As is commonly accepted, this Article refers to “sex” as a biological concept and uses the term “gender” as a social construct. See Rebecca A. Nebel et al., Understanding the Impact of Sex and Gender in Alzheimer’s Disease: A Call to Action, 14 Alzheimer’s & Dementia 1171, 1172 (2018); Becker et al., supra note 5, at 136. The issues discussed in this Article may have potentially unique implications for transgender or intersex individuals, but this is beyond the scope of this Article. The neuroscience studies on sex-based brain differences are less developed with regard to transgender or intersex individuals; as the science develops, further writings could explore this issue more fully. See infra note 24.
 For an excellent overview of the challenges of interpreting the studies in this area, see Cordelia Fine, Daphna Joel & Gina Rippon, Eight Things You Need To Know About Sex, Gender, Brains, and Behavior: A Guide for Academics, Journalists, Parents, Gender Diversity Advocates, Social Justice Warriors, Tweeters, Facebookers, and Everyone Else, Scholar & Feminist Online: Neurogenderings (2019), http://sfonline.barnard.edu/neurogenderings/eight-things-you-need-to-know-about-sex-gender-brains-and-behavior-a-guide-for-academics-journalists-parents-gender-diversity-advocates-social-justice-warriors-tweeters-facebookers-and-ever [https://perma.cc/63YA-ASUB].
 Ruben C. Gur & Raquel E. Gur, Complementarity of Sex Differences in Brain and Behavior: From Laterality to Multimodal Neuroimaging, 95 J. Neurosci. Rsch. 189, 189 (2017) [hereinafter Gur & Gur, Complementarity].
 See Larry Cahill, An Issue Whose Time Has Come, 95 J. Neurosci. Rsch. 12, 12 (2017) (stating that many neuroscientists feared that in pursuing this research “establishing that males and females are not the same in some aspect of brain function meant establishing that they were not equal . . . [, an] assumption [that] is false and deeply harmful”).
 See Becker et al., supra note 5, at 137, 142, 143. Some scientists have suggested that sex differences may have roots in evolution. See Leonardo Christov-Moore et al., Empathy: Gender Effects in Brain and Behavior, 46 Neurosci. & Biobehav. Revs. 604, 604–06 (2014). Sex differences in neurochemistry and hormonal levels have also been partially attributed to evolution forces driving specific changes in animal behavior. See Shelley E. Taylor et al., Biobehavioral Responses to Stress in Females: Tend-and-Befriend, Not Fight-or-Flight, 107 Psych. Rev. 411, 411 (2000). Discussion of these results requires careful attention to and caution against propagating neurosexism. Linda McClain, Nature, Culture, and Social Engineering: Reflections on Evolution and Equality, in NOMOS: Evolution and Morality 347, 359, 365–66 (2012). One danger of the essentialism line of thinking is that it fails to take into account neuroplasticity and lifetime experiences. See Bentley et al., supra note 10.
 See Becker et al., supra note 5, at 137.
 See Joel & Fine, supra note 2 (acknowledging that there are group-level differences in brain and behavior and noting the important difference between group-level and individual-level phenomena).
 See Bryant et al., supra note 12 (“[F]eminist scientists have invited us to pay more attention to intra-sex/gender variability and inter-sex/gender overlap, rather than using sex/gender as a dichotomous variable . . . .”).
 See Stuart J. Ritchie et al., Sex Differences in the Adult Human Brain: Evidence from 5216 UK Biobank Participants, 28 Cerebral Cortex 2959, 2960 (2018).
 Cahill, Why Sex Matters, supra note 10, at *2; see generally Bryant et al., supra note 12 (criticizing research in this field and calling for interventions such as “running empirical tests of randomization control and permutation analyses to protect against false positives, calculating measures of both difference . . . and overlap/similarity between groups, and reporting null results”).
 For example, the stereotype threat effect, in which stereotypes can affect behavior, requires caution when reporting observed group differences. See Bentley et al., supra note 10. Furthermore, our societal view of sex and gender is changing, and neuroscience research could ultimately reject a binary paradigm of sex-based brain differences. See Becker et al., supra note 5, at 142; Nienke M. Nota et al., Brain Functional Connectivity Patterns in Children and Adolescents with Gender Dysphoria: Sex-Atypical or Not?, 86 Psychoneuroendocrinology 187, 187, 193–94 (2017). Slippery slope issues in law abound—for instance, we do not want to open the door to allowing employers to use data on sex-based brain differences for privileging hiring in a field. This would be reminiscent of debates of earlier generations surrounding hiring male nurses or male flight attendants. See Leslie M. Kerns, A Feminist Perspective: Why Feminists Should Give the Reasonable Woman Standard Another Chance, 10 Colum. J. Gender & L. 195, 200, 213–14, 219 (2001) (describing the evolution of the reasonable man standard to the reasonable person standard, that ignores sex disparities in economic and professional status as a result of women being pigeonholed into “feminized” labor sectors, which required little professional education and provided for little mobility or pay).
 See M.E. Kret & B. De Gelder, A Review on Sex Differences in Processing Emotional Signals, 50 Neuropsychologia 1211, 1211–12 (2012) (criticizing the field for reaching conclusions that reflect stereotypes, even when data could be interpreted in many ways); Becker et al., supra note 5, at 142; Deboleena Roy, About this Issue, Scholar & Feminist Online: Neurogenderings (2019), http://sfonline.barnard.edu/neurogenderings/about-this-issue [https://perma.cc/N23Y-CTSJ] (discussing the need to “move us beyond essentializing and biologically deterministic frameworks”).
 See Becker et al., supra note 5, at 141.
 McCarthy et al., supra note 9, at 2241–47; Becker et al., supra note 5, at 141–42. McCarthy also includes in the third category, “sex convergence and divergence.” McCarthy et al., supra note 9, at 2242. Becker adds a fourth category, population (normative) sex differences, which describes when the average number of males/females with a feature or outcome differ. For example, more males are mathematicians than females, which may be explained by individual experiences and sociocultural factors that can affect males and females differently. Becker et al., supra note 5, at 141–42. Noting that the field is “fraught with interpretational problems,” Bryant suggests that differences in traits should be referred to as sex differences, reserving dimorphism labels only when traits in males and females do not overlap. Bryant et al., supra note 12.
 Cahill, Why Sex Matters, supra note 10, at *2.
 See Zeenat F. Zaidi, Gender Differences in Human Brain: A Review, 2 Open Anatomy J. 37, 39 n.37 (2010) https://benthamopen.com/contents/pdf/TOANATJ/TOANATJ-2-37.pdf [https://perma.cc/989C-BHNW].
 Jay N. Giedd et al., Quantitative Magnetic Resonance Imaging of Human Brain Development: Ages 4–18, 6 Cerebral Cortex 551, 551–60 (1996).
 Kelly P. Cosgrove, Carolyn M. Mazure & Julie K. Staley, Evolving Knowledge of Sex Differences in Brain Structure, Function, and Chemistry, 62 Biological Psych. 847, 847 (2007); John S. Allen et al., Sexual Dimorphism and Asymmetries in the Gray-White Composition of the Human Cerebrum, 18 Neuroimage 880, 880–81 (2003); cf. Bryant et al., supra note 12 (arguing that “difference . . . is only valid when appropriate statistical corrections for body size are applied” and noting replication problems and methodological disagreement within the field).
 Cahill, Why Sex Matters, supra note 10, at *2.
 Cosgrove et al., supra note 31.
 Id.; but see Bryant et al., supra note 12 (“[H]ippocamp[i] . . . are not sexually dimorphic as previously claimed.”).
 Cahill, Why Sex Matters, supra note 10, at *2–5; see also Ruben C. Gur, Tamara Bockow & Raquel E. Gur, Gender Differences in the Functional Organization of the Brain, in Principles of Gender-Specific Medicine 75, 80 (2d ed. 2010) (noting that in his studies, “Cahill concludes that imaging studies consistently find that the hippocampus is larger in women compared to men when adjusted for brain size.”). However, a recent study and meta-analysis of MRI images concludes that there are no sex differences in hippocampal volume. Gabor Perlaki et al., Are There Any Gender Differences in the Hippocampus Volume After Head-Size Correction? A Volumetric and Voxel-Based Morphometric Study, 570 Neurosci. Letters 119, 119 (2014) (study); Anh Tan et al., The Human Hippocampus Is Not Sexually-Dimorphic: Meta-Analysis of Structural MRI Volumes, 124 NeuroImage 350, 350 (2016) (meta-analysis).
 Chris Armoskus et al., Identification of Sexually Dimorphic Genes in the Neonatal Mouse Cortex and Hippocampus, 1562 Brain Rsch. 23, 23 (2014).
 Akiko Uematsu et al., Developmental Trajectories of Amygdala and Hippocampus from Infancy to Early Adulthood in Healthy Individuals, 7 PLOS ONE *1, *6–7 (2012), https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0046970&type=printable [https://perma.cc/53DU-F9SS].
 L. A. M. Galea et al., Sex, Hormones and Neurogenesis in the Hippocampus: Hormonal Modulation of Neurogenesis and Potential Functional Implications, 25 J. Neuroendocrinology 1039, 1039 (2013).
 Deanne K. Thompson et al., MR-Determined Hippocampal Asymmetry in Full-Term and Preterm Neonates, 19 Hippocampus 118, 119 (2009) (noting that preterm infants experiencing stressors, and thus potentially implicating hippocampal development, “often have cognitive and learning deficits, memory impairments, and increased risk of neuropsychological disorders such as attention deficit hyperactivity disorder”). While people with stress-related and other neuropsychological disorders consistently are shown to have smaller hippocampi, see Tan et al., supra note 36, at 350, one study suggests that smaller size is a vulnerability for stress disorders and not a consequence. Lenita Lindgren, Jan Bergdahl & Lars Nyberg, Longitudinal Evidence for Smaller Hippocampus Volume as a Vulnerability Factor for Perceived Stress, 26 Cerebral Cortex 3527, 3528 (2016).
 Cahill, Why Sex Matters, supra note 10, at *3.
 Megan M. Filkowski et al., Sex Differences in Emotional Perception: Meta Analysis of Divergent Activation, 147 NeuroImage 925, 926, 929 (2017). Similar differences have been demonstrated in male and female rats. Bruce S. McEwen & Teresa A. Milner, Understanding the Broad Influence of Sex Hormones and Sex Differences in the Brain, 95 J. Neurosci. Rsch. 24, 29 (2017).
 Matthew Bellace, J. Michael Williams, Feroze B. Mohamed & Scott H. Faro, An fMRI Study of the Activation of the Hippocampus by Emotional Memory, 123 Int’l. J. Neurosci. 121, *4–5 (2013) [https://perma.cc/W2BP-L9KS] (showing hippocampal response sex differences in human subjects resulting from exposure to emotional stimuli, including words and images). In one study, decreasing left hippocampal size appeared connected with verbal memory decline in women, but decreasing bilateral hippocampus size had no link to memory decline in men. Martin A. Ystad et al., Hippocampal Volumes Are Important Predictors for Memory Function in Elderly Women, 9 BMC Med. Imaging 17, *11–12 (2009), https://bmcmedimaging.biomedcentral.com/track/pdf/10.1186/1471-2342-9-17 [https://perma.cc/CEV5-EVUH].
 See generally Elizabeth I. Martin, Kerry J. Ressler, Elisabeth Binder & Charles B. Nemeroff, The Neurobiology of Anxiety Disorders: Brain Imaging, Genetics, and Psychoneuroendocrinology, 32 Psychiatric Clinics N. Am. 549 (2009) (discussing the role of the amygdala in mood and other anxiety disorders).
 Jill M. Goldstein et al., Normal Sexual Dimorphism of the Adult Human Brain Assessed by In Vivo Magnetic Resonance Imaging, 11 Cerebral Cortex 490, 492 (2001); Ritchie et al., supra note 22, at 2969.
 See Uematsu et al., supra note 38, at *6. However, one meta-analysis found no significant difference in amygdala size between sexes when controlling for overall brain size differences. See generally Dhruv Marwha, Meha Halari & Lise Eliot, Meta-Analysis Reveals a Lack of Sexual Dimorphism in Human Amygdala Volume, 147 NeuroImage 282 (2017) (stating that amygdala volume “is not selectively enhanced in human males, as often claimed”). Another study found only moderate sex differences in amygdala size. See Lutz Jäncke, Susan Mérillat, Franziskus Liem & Jürgen Hänggi, Brain Size, Sex, and the Aging Brain, 36 Human Brain Mapping 150, 160, 163 (2015).
 Uematsu et al., supra note 38, at *6.
 Id. at *8. Data from rat models suggests that sex-based differences may occur early in development and vary further with puberty and sexual experience. Mariana Zancan et al., Remodeling of the Number and Structure of Dendritic Spines in the Medial Amygdala: From Prepubertal Sexual Dimorphism to Puberty and Effect of Sexual Experience in Male Rats, 48 Eur. J. Neurosci. 1851, 1861 (2018).
 See Jennifer S. Stevens & Stephan Hamann, Sex Differences in Brain Activation to Emotional Stimuli: A Meta-Analysis of Neuroimaging Studies, 50 Neuropsychologia 1578, 1588 (2012); Cahill, Why Sex Matters, supra note 10, at *4.
 Cahill, Why Sex Matters, supra note 10, at *4.
 See Filkowski et al., supra note 43, at 929. Laterality may explain why individuals are better able to recognize correctly the facial expressions in faces of their own sex: When recalling fearful faces of one’s sex, the left amygdala tends to be more active in women while the right amygdala shows greater activity in men. Kret et al., supra note 25, at 1216. Additionally, testosterone appears to increase the reactivity of the amygdala, though testosterone and progesterone appear to influence the amygdala’s connection with other regions of the brain in diverging ways. G. A. van Wingen et al., Gonadal Hormone Regulation of the Emotion Circuitry in Humans, 191 Neurosci. 38, 43 (2011).
 See generally Maria Mpakopoulou et al., Stereotactic Amygdalotomy in the Management of Severe Aggressive Behavioral Disorders, 25 Neurosurgical Focus 1 (2008) (discussing the surgical treatment of amygdala for severe aggressive behavioral disorders).
 See generally Jonathan W. VanRyzin et al., Microglial Phagocytosis of Newborn Cells Is Induced by Endocannabinoids and Sculpts Sex Differences in Juvenile Rat Social Play, 102 Neuron 435 (2019) (“Steroid-mediated masculinization of the rat amygdala during perinatal development produces higher levels of juvenile rough-and-tumble play by males.”).
 Id. The functioning of the amygdala likely plays a role in bipolar disorder. See Leslie A. Hulvershorn et al., Neural Activation During Facial Emotion Processing in Unmedicated Bipolar Depression, Euthymia, and Mania, 71 Biological Psych. 603, 607 (2012). Age may further implicate sex differences in this condition. Yanqing Tang et al., Age-Specific Effects of Structural and Functional Connectivity in Prefrontal-Amygdala Circuitry in Women with Bipolar Disorder, 18 BMC Psych. 177, *4–6 (2018), https://bmcpsychiatry.biomedcentral.com/track/pdf/10.1186/s12888-018-1732-9 [https://perma.cc/LCN8-3J5C].
 Ruud van den Bos, Judith Homberg & Leonie de Visser, A Critical Review of Sex Differences in Decision-Making Tasks: Focus on the Iowa Gambling Task, 238 Behav. Brain Rsch. 95, 100, 102 (2013).
 See Kelly L. Evans & Elizabeth Hampson, Sex Differences on Prefrontally-Dependent Cognitive Tasks, 93 Brain & Cognition 42, 43 (2015) (citing several studies that suggest that the male advantage in object reversal may be attributed to “only a short-term difference in developmental timing”); see also id. at 49 (suggesting evidence that males may perform better in prefrontal-cortex-associated decision-making activities involving optimizing outcomes by preferring options with more long-term advantages).
 A review of over fifty brain scan studies found greater stimulation in one section of the prefrontal cortex, the medial prefrontal cortex, in men in response to visually observed emotional stimuli. Filkowski et al., supra note 43, at 926, 928.
 Michael Koenigs & Jordan Grafman, Post-Traumatic Stress Disorder: The Role of Medial Prefrontal Cortex and Amygdala, 15 Neuroscientist 540, *1 (2009) [https://perma.cc/T2DJ-2RQH].
 See Ezequiel Marron Fernandez de Velasco et al., Sex Differences in GABA(B)R-GIRK Signaling in Layer 5/6 Pyramidal Neurons of the Mouse Prelimbic Cortex, 95 Neuropharmacology 353, 357 (2015).
 See N. Carrier & M. Kabbaj, Sex Differences in Social Interaction Behaviors in Rats Are Mediated by Extracellular Signal-Regulated Kinase 2 Expression in the Medial Prefrontal Cortex, 212 Neurosci. 86, 88, 90 (2012).
 See Georgina E. Fenton et al., Persistent Prelimbic Cortex Activity Contributes to Enhanced Learned Fear Expression in Females, 21 Learning & Memory 55, 55 (2014). Other studies in rats point to few sex differences in medial prefrontal cortex- and amygdala-mediated fear control. Tina M. Gruene et al., Sex-Specific Neuroanatomical Correlates of Fear Expression in Prefrontal-Amygdala Circuits, 78 Biological Psych. 186, 191 (2015).
 Cahill, Why Sex Matters, supra note 10, at *5 (listing neurotransmitter systems including serotonin, GABA, acetylcholine, vasopressin, opioid receptors, and monoamines). Some evidence suggests that there may be an age component related to sex differences as well. See generally Lara M. Wierenga et al., Unraveling Age, Puberty and Testosterone Effects on Subcortical Brain Development Across Adolescence, 91 Psychoneuroendocrinology 105, 105 (2018) (describing “the complex interactions between chronological age and pubertal maturational changes,” and finding “puberty unique changes in brain structure that are sex specific”).
 Lusi Madisha, Difference Between Serotonin and Dopamine, DifferenceBetween.net (Oct. 18, 2019), http://www.differencebetween.net/science/health/difference-between-serotonin-and-dopamine [https://perma.cc/FD4U-XZBQ].
 S. Nishizawa et al., Differences Between Males and Females in Rates of Serotonin Synthesis in Human Brain, 94 PNAS 5308, 5312 (1997).
 Cosgrove et al., supra note 31, at 851. This may have implications for the higher incidence of Parkinson’s disease in men. Id.
 Raquel E. Gur & Ruben C. Gur, Sex Differences in Brain and Behavior in Adolescence: Findings from the Philadelphia Neurodevelopmental Cohort, 70 Neurosci. & Biobehav. Revs. 159, 162 (2016) [hereinafter Gur & Gur, Sex Differences]. However, hormonal effects on brain organization “can dynamically change within relatively short periods throughout life” and not just during adolescence. Markus Hausmann, Why Sex Hormones Matter for Neuroscience: A Very Short Review on Sex, Sex Hormones, and Functional Brain Asymmetries, 95 J. Neurosci. Rsch. 40, 40 (2017).
 Becker et al., supra note 5, at 142.
 Cahill, Why Sex Matters, supra note 10, at *7.
 Debra A. Bangasser & Brittany Wicks, Sex-Specific Mechanisms for Responding to Stress, 95 J. Neurosci. Rsch. 75, 75 (2017); cf. Gungor et al., supra note 8 (stating that hormones do not explain women’s greater PTSD risk, but they should be studied to improve our understanding of the neurobiology of fear processing in both men and women).
 Abigail Laman-Maharg & Brian C. Trainor, Stress, Sex, and Motivated Behaviors, 95 J. Neurosci. Rsch. 83, 83 (2017).
 Christian J. Merz & Oliver T. Wolf, Sex Differences in Stress Effects on Emotional Learning, 95 J. Neurosci. Rsch. 93, 93 (2017).
 Meghna Ravi, Jennifer S. Stevens & Vasiliki Michopoulos, Neuroendocrine Pathways Underlying Risk and Resilience to PTSD in Women, 55 Frontiers in Neuroendocrinology *1, *1 (2019) [https://perma.cc/W2NC-A82S].
 Id. at *2.
 See id. (discussing the role of estradiol, progesterone, and allopregnanolone in fear psychophysiology).
 See Becker et al., supra note 5, at 136.
 See Marina Cholanian et al., Digital Holographic Microscopy Discriminates Sex Differences in Medial Prefrontal Cortex GABA Neurons Following Amphetamine Sensitization, 124 Pharmacology, biochemistry & Behav. 326, 331–32 (2014) (finding high estradiol in rats to be associated with greater behavioral hyperactivity following amphetamine treatment, which suggests a hormonal component behind sex differences in levels of drug use and addiction).
 Cahill, Why Sex Matters, supra note 10, at *5 (citing J. K. Zubieta, R. F. Dannals & J. J. Frost, Gender and Age Influences on Human Brain Mu-Opioid Receptor Binding Measured by PET, 156 Am. J. Psych. 842, (1999)) (documenting sex differences in opioid peptides that bind to opioid receptors in the brain).
 Khalid H. Jawabri & Sandeep Sharma, Physiology, Cerebral Cortex Functions, StatPearls (2019), https://www.ncbi.nlm.nih.gov/books/NBK538496 [https://perma.cc/TU9G-9MWA].
 Jay N. Giedd, Armin Raznahan, Kathryn L. Mills & Rhoshel K. Lenroot, Review: Magnetic Resonance Imaging of Male/Female Differences in Human Adolescent Brain Anatomy, 3 Biology of Sex Differences 19, *2 (2012), https://bsd.biomedcentral.com/track/pdf/10.1186/2042-6410-3-19 [https://perma.cc/RS2A-VXGN]; Armin Raznahan et al., How Does Your Cortex Grow?, 31 J. Neurosci. 7174, 7176 (2011).
 A. Kadir Mutlu et al., Sex Differences in Thickness, and Folding Developments Throughout the Cortex, 82 NeuroImage 200, 204 (2013).
 See id. at 203–05.
 Robert M. Sargis, An Overview of the Hypothalamus: The Endocrine System’s Link to the Nervous System, EndocrineWeb (Apr. 8, 2015), https://www.endocrineweb.com/endocrinology/overview-hypothalamus [https://perma.cc/UC72-FGFG].
 Cindy F. Yang et al., Sexually Dimorphic Neurons in the Ventromedial Hypothalamus Govern Mating in Both Sexes and Aggression in Males, 153 Cell 896, 898 (2013).
 Nirupa Goel et al., Sex Differences in the HPA Axis, 4 Comprehensive Physiology 1121, 1145 (2014).
 Samara A.M. Bobzean, Aliza K. DeNobrega & Linda I. Perrotti, Sex Differences in the Neurobiology of Drug Addiction, 259 Experimental Neurology 64, 69 (2014).
 Filkowski et al., supra note 43, at 925 (stating that the study observed sex differences in emotional function in the brainstem for the first time). The corpus callosum (“CC”), which connects the left side of the brain to the right side, shows sex-based differences; on average, female CCs are larger than those of males. Ralph L. Holloway, In the Trenches with the Corpus Callosum: Some Redux of Redux, 95 J. Neurosci. Rsch. 11, 12 (2017). But see Bryant et al., supra note 12 (disputing findings of sex-based differences in CC). Abnormalities in the CC have been associated with autism spectrum disorder, Christine Wu Nordahl et al., Sex Differences in the Corpus Callosum in Preschool-aged Children with Autism Spectrum Disorder, 6 Mol. Autism 26, *8–10 (2015), https://molecularautism.biomedcentral.com/track/pdf/10.1186/s13229-015-0005-4 [https://perma.cc/2RL2-GWP2], and bipolar disorder, Adrian J. Lloyd et al., Corpus Callosum Changes in Euthymic Bipolar Affective Disorder, 204 Brit. J. Psychiatry 129, 129 (2014).
 Ritchie et al., supra note 22, at 2960; Gur & Gur, Sex Differences, supra note 69, at 159–60.
 Gur & Gur, Complementarity, supra note 16, at 189.
 Gur & Gur, Sex Differences, supra note 69, at 166.
 Id. at 167.
 McEwen & Milner, supra note 43, at 33.
 Amber N.V. Ruigrok et al., A Meta-Analysis of Sex Differences in Human Brain Structure, 39 Neurosci. & Behav. Revs. 34, 35 (2014).
 Kathryn M. Abel, Richard Drake & Jill M. Goldstein, Sex Differences in Schizophrenia, 22 Internal Rev. Psychiatry 417, 417 (2010).
 Gur & Gur, Complementarity, supra note 16, at 193.
 Ruigrok et al., supra note 95, at 35.
 Ravi et al., supra note 75; Bangasser & Wicks, supra note 72, at 75.
 See Becker et al., supra note 5, at 136.
 See Brooks & Clayton, supra note 5, at 15.
 See id.
 See id.
 McEwen & Milner, supra note 43, at 33; Robert Y. North et al., Electrophysiological and Transcriptomic Correlates of Neuropathic Pain in Human Dorsal Root Ganglion Nerves, 142 Brain 1215, 1224 (2019) (suggesting that the presence of sex-specific differences in immune response and neuronal plasticity is related to radicular/neuropathic pain); see Patti Neighmond, Women May Be More Adept Than Men at Discerning Pain, NPR (Aug. 26, 2019, 5:06 AM), https://www.npr.org/741926952 [https://perma.cc/D48E-MG34].
 See Gur & Gur, Complementarity, supra note 16, at 189.
 Cahill, Why Sex Matters, supra note 10, at *6 (citing examples of differences in the disease pathology of Alzheimer’s, schizophrenia, and addiction between men and women); Gungor et al., supra note 8, at 3 (questioning whether trauma type, rather than pre-existing vulnerability, explains high rates of PTSD in women).
 See Mayo Moran, Rethinking the Reasonable Person: An Egalitarian Reconstruction of the Objective Standard 6 (2003) (explaining that the reasonableness standard has “powerful links to equality”); but see Martha Chamallas, Feminist Legal Theory and Tort Law, in Research Handbook on Feminist Jurisprudence 387 (2019) (arguing that gender inequalities are built into the “deep structures” of tort law through its failure to recognize claims of particular importance to women, such as claims for witnessing harm to their young children; third-party liability for sexual harassment, coercion, and violence; claims arising from reproductive injuries; and gender-biased calculations of damages) [hereinafter Chamallas, Feminist Legal Theory and Tort Law].
 Courts are inconsistent in their approaches to admitting expert testimony on general group-level phenomena and applying it to specific cases. See David L. Faigman, John Monahan & Christopher Slobogin, Group to Individual (G2i) Inference in Scientific Expert Testimony, 81 U. Chi. L. Rev. 417, 432–40 (2014) (examining courts’ use of general expert testimony on eyewitness testimony, medical and psychological conditions, employment discrimination, and forensic identification). Courts exercise caution when it comes to proffering novel syndrome or theory evidence to be applied to the case at hand. Id. at 434 (citing examples of rape-trauma syndrome and battered woman syndrome).
 See Daubert v. Merrell Dow Pharm., 509 U.S. 579, 580 (1993).
 See Graham v. Florida, 560 U.S. 48, 68 (2010) (“[D]evelopments in psychology and brain science continue to show fundamental differences between juvenile and adult minds.”); Roper v. Simmons, 543 U.S. 551, 553 (2005) (stating that the Constitution bars capital punishment for juvenile offenders and recognizing categorical differences between juveniles and adults); Atkins v. Virginia, 536 U.S. 304, 304 (2002) (rejecting the death penalty for the intellectually disabled); Jozsef Meszaros, Achieving Peace of Mind: The Benefits of Neurobiological Evidence for Battered Women Defendants, 23 Yale J.L. & Feminism 117, 120 (2011) (arguing for the integration of neurobiological evidence into the defense of battered women); see also Brown v. Ent. Merchs. Ass’n, 564 U.S. 786, 852 (2011) (Breyer, J., dissenting) (citing “cutting-edge neuroscience” to support the argument that violent video games are linked to aggressive behavior).
 Benjamin C. Zipursky, Reasonableness In and Out of Negligence Law, 163 U. Pa. L. Rev. 2131, 2134 (2015).
 See Alan Calnan, Essay, The Nature of Reasonableness, 105 Cornell L. Rev. Online 81, 81 (2020) (“[R]easonableness is one of the foundational concepts of American law. . . .”); Brandon L. Garrett, Constitutional Reasonableness, 102 Minn. L. Rev. 61, 69–70 (describing use of the reasonableness concept across the legal landscape); Robert Unikel, “Reasonable” Doubts: A Critique of the Reasonable Woman Standard in American Jurisprudence, 87 Nw. L. Rev. 326, 327 (1992) (“‘[R]easonableness’ has gained a prominent position in almost every area of American law. A general survey reveals that the concept of ‘reasonableness’ is a standard of decisionmaking in administrative law, bailment law, constitutional law, contract law, criminal law, tort law, and the law of trusts.”); Frédéric G. Sourgens, Reason and Reasonableness: The Necessary Diversity of the Common Law, 67 Me. L. Rev. 73, 74 (2014) (“Reasonableness is the keystone of the common law.”); Zipursky, supra note 115, at 2135–49 (listing examples of the use of reasonableness in law).
 See Moran, supra note 111, at 6 (stating that the reasonableness standard has “powerful links to equality”).
 Garrett, supra note 116, at 62 (“[T]he flexibility and malleability of reasonableness standards [in constitutional law] accounts for their ubiquity and utility. . . .”); id. at 70 (quoting James Gibson, Doctrinal Feedback and (Un)reasonable Care, 94 Va. L. Rev. 1641, 1643 (2008)) (“In tort law, the flexibility of the concept of reasonable care may be a weakness, but also its strength, giving courts the ability . . . ‘to arrive at the correct judgment in a fact-dependent context,’ even if the concept is ‘frustratingly imprecise’. . . .”); Sourgens, supra note 116, at 74 (“The edifice of the common law would collapse but for the balance struck between diverse and competing ends and interests by ‘reasonableness.’”).
 See Restatement (Third) of Torts: Liability for Physical & Emotional Harm § 3 (Am. Law Inst. 2010) (“A person acts negligently if the person does not exercise reasonable care under all the circumstances.”).
 See Daniel B. Dobbs, Paul T. Hayden & Ellen M. Bublick, Hornbook on Torts § 10.5 (2d ed. 2016).
 See Kerns, supra note 24, at 210–12 (2001) (describing the evolution of the reasonable man standard to the reasonable person standard).
 Alan D. Miller & Ronen Perry, The Reasonable Person, 87 N.Y.U. L. Rev. 323, 325 (2012).
 Much ink has been spilled over whether the reasonable person standard is normative or descriptive or both. See id. at 323 (“[N]ormative definitions [of reasonableness] are categorically preferable to positive definitions, because the latter are logically unacceptable. . . .”); Kevin P. Tobia, How People Judge What is Reasonable, 70 Ala. L. Rev. 293, 296 (2018) (explaining that the reasonableness standard “is best understood as a hybrid notion that is partly statistical and partly prescriptive”); Garrett, supra note 116, at 61; Sourgens, supra note 116, at 78. See Moran, supra note 111, at 7 (describing tension between descriptive and normative components of the reasonable person standard).
 These ideals include economic efficiency, fairness, community values, utilitarianism, and virtue. See Calnan, supra note 116, at 3 (arguing that reasonableness concept has physiological origins and susceptible to scientific investigation); Sourgens, supra note 116, at 78 (explaining that the common law “relies upon inconsistent pragmatic, formalist, and utilitarian reasonableness paradigms”); Zipursky, supra note 115, at 2142 (proposing a theory of reasonableness as one of mutuality); Heidi Li Feldman, Prudence, Benevolence, and Negligence: Virtue Ethics and Tort Law, 74 Chi.-Kent L. Rev. 1431, 1432 (2000) (explaining tort doctrine from a virtue ethics viewpoint).
 See The T. J. Hooper v. N. Barge Corp., 60 F.2d 737, 740 (2d Cir. 1932).
 See Zipursky, supra note 115, at 2149–50; Tobia, supra note 123, at 342 (stating that the hybrid view seeks to avoid some of the absurdities of either a strictly statistical standard—raising problems of average accidents and reasonable racism—or a strictly prescriptive view—protecting consumers only in situations in which they ought to be misled); Moran, supra note 111, at 2 (“The way that the reasonable person seamlessly intertwines the normative and descriptive may be one source of his appeal . . . .”).
 See Dobbs et al., supra note 120, § 9.7 (stating that the reasonable person approach “reflects the law’s strong commitment to an objective standard of behavior”); Unikel, supra note 116, at 330.
 Unikel, supra note 116, at 326.
 See Moran, supra note 111, at 10 (drawing on John Rawls’s discussion of the rule of law which “clarifies that under a system of the rule of law, judicial decision-making must at a minimum exhibit a certain kind of equality across cases”).
 Vaughan v. Menlove (1837) 132 Eng. Rep. 490, 493 (C.P.).
 See id.
 Dobbs et al., supra note 120, §§ 10.8, 10.12.
 Id. § 10.8; Kristin Harlow, Applying the Reasonable Person Standard to Psychosis: How Tort Law Unfairly Burdens Adults with Mental Illness, 68 Ohio St. L.J. 1733, 1738, 1743 (2007). As Justice Holmes stated, the standards applied to the reasonable person are “standards of general application. The law takes no account of the infinite varieties of temperament, intellect, and education which make the internal character of a given act so different in different men.” Oliver Wendell Holmes, The Common Law 108 (1881). Thus, an external, objective standard of care avoids arbitrary interpretation and unfairness to other members of the community.
 The reasonableness standard is defended by its “unifying power, even if, in practice, what is reasonable is highly fact-dependent and will require fact-sensitive and industry-sensitive judgments.” Garrett, supra note 116, at 108 (citing David Zaring, Rule by Reasonableness, 63 Admin. L. Rev. 525, 538–39 (2011)).
 See Mark P. Gergen, The Jury’s Role in Deciding Normative Issues in the American Common Law, 68 Fordham L. Rev. 407, 424–25 (1999); see, e.g., 7A Mich. Civ. Prac. Forms § 127:30 (2020) (“The law does not say what a reasonably careful person would do or would not do under the circumstances. That is for you to decide.”); cf. Moran, supra note 111, at 305–06 (discussing the difficulties of determining what behavior is reasonable).
 Tort law sometimes takes into account objectively verifiable physical characteristics in certain groups, such as the disabled, in judging behavior. Dobbs et al., supra note 120, § 10.9; see Restatement (Second) of Torts § 283A (Am. Law Inst. 1965) (stating that for children, the reasonable person standard can take into account the perspective of those of “like age, intelligence, and experience under like circumstances”). Higher skill is another exception. Tort law measures professional standards by using external measures of skill of the profession. The prototype is medical malpractice, in which we measure a doctor’s treatment of a patient against the treatment of a reasonable doctor in a similar medical field to determine whether the treatment fell below the medical standard of care. Dobbs et al., supra note 120, § 21.6.
 See Moran, supra note 111, at 279–80 (describing how further contextualization and particularization of a reasonableness standard will result in a standard that “more closely approximate[s] the individual being judged”).
 See Restatement (Third) of Torts: Liability for Physical & Emotional Harm § 10 (Am. Law Inst. 2010) (“A child’s conduct is negligent if it does not conform to that of a reasonably careful person of the same age, intelligence and experience . . . .”); Dobbs et al., supra note 120, § 10.14 (stating that children are required to conform to the standard of a child of similar age and abilities); Moran, supra note 111, at 6 (finding that when judging children, courts demand that “the characteristics of the legal person closely mirror those of the actual person whose behaviour is being judged”).
 Restatement (Third) of Torts: Liability for Physical & Emotional Harm § 10.
 Justifications include the belief that children develop cognitive and physical abilities at different rates; children should develop at their own pace; the law should reflect the normative view of what children ought to do; and perhaps the law assumes that others in the community will take care to avoid the consequences of children’s activities. See Betsy J. Grey, Implications of Neuroscience Advances in Tort Law: A General Overview, 12 Ind. Health L. Rev. 671, 682 (2015); Moran, supra note 111, at 9 (suggesting that the special standard for children refers to how normal childhood is, and may reflect our view of their importance to society as opposed to other minority groups); Harlow, supra note 133, at 1740–42 (describing the development of the negligence standard for children); Restatement (Third) of Torts: Liability for Physical & Emotional Harm § 10 cmt. b.
 Cf. Roper v. Simmons, 543 U.S. 551, 569 (2005) (taking age into account for application of the death penalty).
 See Tobia, supra note 123, at 346–47 (finding that the problem of individualization “is important and difficult, and . . . is largely separate from the statistical, prescriptive, and hybrid debate”). See generally David E. Seidelson, Reasonable Expectations and Subjective Standards in Negligence Law: The Minor, the Mentally Impaired, and the Mentally Incompetent, 50 Geo. Wash. L. Rev. 17, 20–26 (1981) (discussing the reasonableness standard as applied to minors).
 See Tobia, supra note 123, at 346–47.
 See id. at 348 (“[E]ven if the statistical view [of the reasonable person standard] only acknowledges features with a statistically significant impact . . . , we will still have far too many individualized reasonableness standards.”); Moran, supra note 111, at 3 (“[W]ithout a clear sense of which qualities of the reasonable person matter normatively and which do not, the standard threatens to disappear into a description of the actual person.”); Tobia, supra note 118, at 349 (“From a prescriptivist perspective, individualization—like reasonableness—is not about statistical patterns of behavior; instead, it is about normatively correct behaviors.”).
 See Moran, supra note 111, at 307 (“[P]ersonification makes it so difficult to articulate a standard that is appropriately sensitive to equality without implying some kind of essential moral and epistemological differences among genders, races, and the like.”).
 Id. at 274.
 See Margo Schlanger, Injured Women Before Common Law Courts, 1860 – 1930, 21 Harv. Women’s L.J. 79, 80–82¬ (1998). A quote often cited as an example is an English court’s description that the “reasonable man” is “the man who takes the magazines at home, and in the evening pushes the lawn mower in his shirt sleeves.” Hall v. Brooklands Auto-Racing Club,  1 K.B. 205, 224.
 Leslie Bender, A Lawyer’s Primer on Feminist Theory and Tort, 38 J. Legal Educ. 3, 22 (1988); Deborah L. Rhode, Justice and Gender: Sex Discrimination and the Law 20 (1991); see also Garrett, supra note 116, at 63 (“Commentators have long critiqued reasonable man and reasonable person standards in common law fields for assuming perspectives that, in fact, bring in non-objective assumptions about conduct.”).
 See Miller & Perry, supra note 122, at 362 (noting how feminist theory, after the change to “reasonable person,” argued that the standard was still given a masculine orientation). Some authors have argued that the reasonable person standard still has a male bias. See Bender, supra note 148, at 22; see generally Caroline Forell, Essentialism, Empathy, and the Reasonable Woman, 1994 U. Ill. L. Rev. 769 (arguing that the reasonableness standard is still male-oriented).
 See Naomi R. Cahn, The Looseness of Legal Language: The Reasonable Woman Standard in Theory and in Practice, 77 Cornell L. Rev. 1398, 1404 (1992) (“The male bias inherent in a standard that explicitly excludes consideration of women as reasonable actors is obvious.”); Nancy S. Ehrenreich, Pluralist Myths and Powerless Men: The Ideology of Reasonableness in Sexual Harassment Law, 99 Yale L.J. 1177, 1178 (1990) (“[D]efinitions of reasonableness often reflect the values and assumptions of a narrow elite . . . .”); Moran, supra note 111, at 199 (“The suspiciously masculine nature of the reasonable person is one of the most long-standing topics of discussion in the general literature on feminism and the law.”).
 See Bender, supra note 148, at 22. As Professor Leslie Bender explained, “[o]ur legal system . . . is a system that resolves problems through male inquiries formulated from distanced, abstract, and acontextual vantage points, while feminism emphasizes relationships, context, and factual particulars for resolving human problems.” Id. at 10–11; see also Rhode, supra note 148, at 20.
 See Patricia A. Cain, Feminist Jurisprudence: Grounding Theories, 4 Berkeley Women’s L.J. 191, 191 (1989) (“What makes any theory particularly feminist is that it is derived from female experience, from a point of view contrary to the dominant male perception of reality.”); Chamallas, supra note 111, at 387 (“The unstated norms in tort doctrines still tend to be based on men’s life experiences.”).
 Bender, supra note 148, at 23 (“When [the reasonable man standard] was converted to ‘reasonable person,’ it still meant ‘person who is reasonable by my standards’ almost exclusively from the perspective of a male judge, lawyer, or law professor . . . .”). Some theorists challenged Bender’s premise that the reasonableness standard is always based on a “male perspective.” See Schlanger, supra note 147, at 85. After examining case studies of nineteenth and early twentieth century cases involving injuries to women, Professor Margo Schlanger argued that these cases demonstrate that, “[f]ar from naively erasing gender by subsuming women into the male category of ‘reasonable men’ or a purportedly neutral, but no less male category of ‘reasonable persons,’ courts actually treated gender as an important factor in assessing appropriate standards of care.” Id. at 84–85. She argued that these cases do not “support a charge of invariable refusal to take account of women’s experience, or of consistent deprecation of women’s capabilities.” Id. at 85.
 As Professor Brandon Garrett observed: “Common criticisms remain that reasonableness tends to be interpreted to reflect standards of care that do not reflect diverse viewpoints, but rather those of reductionist, or majority, or male viewpoints; a non-emotional perspective; or a privileged judicial perspective.” Garrett, supra note 116, at 72; see Moran, supra note 111, at 274 (“The worry for equality seekers is that in the very kinds of cases that most concern them, the presence of widespread ‘unreasonable’—non-egalitarian—beliefs will hold out an alternative reading of reasonableness that enables discriminatory beliefs to feed into the ‘objective’ standard.”).
 E.g., Ellison v. Brady, 924 F.2d 872, 879 (9th Cir. 1991); Rabidue v. Osceola Refin. Co., 805 F.2d 611, 626 (6th Cir. 1986); Jeremy A. Blumenthal, The Reasonable Woman Standard: A Meta-Analytic Review of Gender Differences in Perceptions of Sexual Harassment, 22 L. & Human Behav. 33, 34–35 (1998); Cahn, supra note 150, at 1409; Barbara A. Gutek & Maureen O’Connor, The Empirical Basis for the Reasonable Woman Standard, 51 J. Soc. Issues 151, 152 (1995); Elizabeth L. Shoenfelt et al., Reasonable Person Versus Reasonable Woman: Does It Matter?, 10 Am. U. J. Gender, Soc. Pol’y, & L. 633, 637 (2002). See Moran, supra note 111, at 276–81 (discussing the development, use, and debate around the “reasonable woman” standard).
 Ellison v. Brady, 924 F.2d 872 (9th Cir. 1991).
 Id. at 879.
 EEOC v. Nat’l Educ. Ass’n, 422 F.3d 840, 845–46 (9th Cir. 2005).
 Rabidue v. Osceola Refin. Co., 805 F.2d 611 (6th Cir. 1986).
 Id. at 626–27 (Keith, J., dissenting). According to the Supreme Court, a hostile work environment is one “that a reasonable person would find hostile or abusive.” Harris v. Forklift Sys., Inc., 510 U.S. 17, 21 (1993). In a later case, the Court explained that this “reasonable person” must be viewed “in the plaintiff’s position considering ‘all the circumstances.’” Oncale v. Sundowner Offshore Servs. Inc., 523 U.S. 75, 81 (1998). In determining the view of the reasonable person, the factfinder should undergo “careful consideration of the social context in which particular behavior occurs and is experienced by its target.” Id.; see Moran supra note 117, at 275 (“[C]oncerns about how the reasonable person standard has incorporated ‘ordinary’ male sexual harassment have caused many feminists and even some courts to abandon that standard in favour of a standard premissed [sic] on the ‘reasonable woman.’”).
 See, e.g., Fuller v. Idaho Dep’t of Corr., 865 F.3d 1154, 1162 (9th Cir. 2017); Clayton v. City of Atl. City, 538 F. App’x 124, 128 (3d Cir. 2013); Gray v. Genlyte Grp., Inc., 289 F.3d 128, 133 (1st Cir. 2002); Woods v. Delta Beverage Grp., Inc., 274 F.3d 295, 301 (5th Cir. 2001). The Fifth, Sixth, Eighth, and Eleventh Circuits have rejected application of a reasonable woman standard, however. See Alyssa Agostino, The Reasonable Woman Standard’s Creation of the Reasonable Man Standard: The Ethical and Practical Implications of the Two Standards and Why They Should Be Abandoned, 41 J. Legal Pro. 339, 339 (2017).
 Jolynn Childers, Is There a Place for a Reasonable Woman in the Law? A Discussion of Recent Developments in Hostile Environment Sexual Harassment, 42 Duke L.J. 854, 896 (1993).
 Cahn, supra note 150, at 1415.
 See Childers, supra note 162, at 889–90 (noting that feminist critics argued that any reasonable woman standard will reflect a “white, upper-middle-class bias”). Others suggest that the reasonable woman standard would allow application of a standard that reflects different social circumstances, by further contextualizing the standard. See Cahn, supra note 150, at 1417–20, 1435.
 This brief description vastly oversimplifies a diverse and rich field of thinking and does not attempt to capture all the various strains of thought in this area. For an excellent overview of different feminist jurisprudence theories and their varying threads, see generally Cynthia Grant Bowman, Laura A. Rosenbury, Deborah Tuerkheimer & Kimberly A. Yuracko, Feminist Jurisprudence: Cases and Materials (5th ed. 2018), and Martha Minow, Making all the Difference: Inclusion, Exclusion, and American Law (1990).
 Moran, supra note 111, at 278.
 Nancy Levit & Robert R.M. Verchick, Feminist Legal Theory: A Primer 18 (2d ed. 2016).
 Minow, supra note 165, at 20.
 See West, supra note 1, at 991.
 Ruth Bader Ginsburg & Barbara Flagg, Some Reflections on the Feminist Legal Thought of the 1970s, 1989 U. Chi. Legal F. 9, 11 (1989); see id. at 14–15, 17. We often refer to this as leveling the playing field, to take away public-sphere obstacles to equal competition.
 As Professors Alan Miller and Ronen Perry explained,
Miller & Perry, supra note 122, at 363.
 See Robin L. West, The Difference in Women’s Hedonic Lives: A Phenomenological Critique of Feminist Legal Theory, 15 Wis. Women’s L.J. 149, 149–53 (2000).
 Two branches of this line of thinking—cultural feminism, which demands reevaluation of traditionally feminine activities and traits, and radical feminism, which condemns sexual exploitation—reflect this focus. See Martha Chamallas & Jennifer B. Wriggins, The Measure of Injury: Race, Gender, and Tort Law 7 (2010).
 Ann Bartow, Legal Theory Lexicon 061: Feminist Legal Theory, Legal Theory Lexicon (Nov. 19, 2006), http://lsolum.typepad.com/legal_theory_lexicon/2006/11/legal_theory_le.html [https://perma.cc/7342-HJNL].
 As Professor Naomi Cahn has argued, egalitarian considerations can be realized in a standard that “subjectively considers the pressure on an individual who is a member of a community with explicit standards for her behavior.” Cahn, supra note 150, at 1436. Miller and Perry reconstitute these feminist approaches as applied to the reasonableness standards into three formulations: “weak,” “intermediate,” and “strong.” Miller & Perry, supra note 122, at 362–63 (2012). The weak formulation would apply some gender aspects to the objective standard. Id. at 362. The intermediate standard—an inclusive one—would include all feminist perspectives, experiences, and capabilities to create a single, neutral reasonable person standard. Id. at 364 (citing Lucinda M. Finley, A Break in the Silence: Including Women’s Issues in a Torts Course, 1 Yale J.L. & Feminism 41, 63–64 (1989)). The strong formulation would subject all persons to a feminine standard of care, such as a duty to rescue regardless of a prior relationship. Id. (citing Carol Gilligan, In a Different Voice: Psychological Theory and Women’s Development 19 (1982)).
 See Kimberle Crenshaw, Demarginalizing the Intersection of Race and Sex: A Black Feminist Critique of Antidiscrimination Doctrine, Feminist Theory and Antiracist Politics, 1989 U. Chi. Legal F. 139, 139–40 (1989); see also Kimberle Crenshaw, Mapping the Margins: Intersectionality, Identity Politics, and Violence Against Women of Color, 43 Stan. L. Rev. 1241, 1245–51 (1991) (showing that women of color experience more violent harm due to intersectional effects). The problem of intersectionality—that experiences are shaped by factors other than sex, such as class, ethnicity, age, race, and disability—is the focus of much of the “third wave” of feminism, starting in the late 1980s. West, supra note 1, at 980 n.12. The intersectionalist view demands that feminists recognize the different societal hierarchies of women since some women are more privileged than others due to these hierarchies. Martha Chamallas, Introduction to Feminist Legal Theory 6–7 (3d ed. 2013) [hereinafter Chamallas, Introduction to Feminist Legal Theory]. As Professor Martha Chamallas stated, “[t]he intersectional move is designed to curb the temptation to speak in universal terms, a habit feminists detest in male-oriented scholarship and language.” Id. at 7. This Article does not seek to marginalize these legitimate considerations nor their influences on behavior. It merely seeks to focus on neuroscientific scholarship available on sex-based brain differences.
 Id. at 319. Relatedly, a major criticism of the reasonable woman standard is its potential failure to recognize that not everyone conforms to the gender stereotype. Miller & Perry, supra note 122, at 363; see Moran, supra note 111, at 278–79.
 This is not to suggest that scientific labels are not value-laden. In fact, when science labels something as normal or pathological, it is to some extent importing notions of value. See Moran, supra note 111, at 145 (“[T]he idea of normal is problematic even in its scientific application.”). Feminist critics point out that seemingly neutral categories in science can distort our understanding of the natural world. Id. at 146 (citing literature on science and gender). The concept of normal has been used to justify unequal treatment of women and the developmentally disabled, along with the exclusion from full privileges of citizenship. Id. at 146–47.
 Dobbs et al., supra note 120, § 29.9.
 See Chamallas, Feminist Legal Theory and Tort Law, supra note 111, at 400, 402. I have argued elsewhere that neuroscience advances may eventually give us ways to validate emotional stress responses and lead us to strike down some of these extra barriers. See Betsy J. Grey, The Future of Emotional Harm, 83 Fordham L. Rev. 2605, 2647 (2015).
 Although courts do not typically apply the same reasonable reaction test to bystander NIED claims, they achieve the same effect through other limitations. See, e.g., Portee v. Jaffee, 417 A.2d 521, 527 (N.J. 1980) (limiting the availability of bystander claims to individuals who witnessed the contemporaneous serious injury or death of a close family member due to a defendant’s negligence). The assumption is that reasonable people would suffer severe emotional distress in that context. Id. (“[T]he scope of recovery must be circumscribed to negligent conduct which strikes at the plaintiff’s basic emotional security.”).
 Dobbs et al., supra note 120, § 29.9.
 See Ragin v. Harry Macklowe Real Estate Co., 6 F.3d 898, 908 (2d Cir. 1993); DiMare v. RealtyTrac, Inc., 714 F. Supp. 2d 199, 211 (D. Mass. 2010) (“To recover for negligent infliction of emotional distress, plaintiff must show that a reasonable person would have suffered the same level of emotional distress under similar circumstances.”); Gammon v. Osteopathic Hosp. of Me., Inc., 534 A.2d 1282, 1285 (Me. 1987); Williamson v. Waldman, 696 A.2d 14, 22 (N.J. 1997).
 Once this test is met, the Third Restatement provides that the plaintiff may then recover for all resulting harm, even if it is unforeseeable, using the traditional “eggshell” plaintiff test of damages. See Restatement (Third) of Torts: Liability for Physical & Emotional Harm § 31 (Am. Law Inst. 2012). The Restatement also provides that the eggshell plaintiff rule applies in cases where the defendant knows about the victim’s unusual vulnerability. Id.
 See Dobbs et al., supra note 120, § 15.11. This rule falls under the general law of proximate cause, which draws a distinction between unexpected type and unexpected extent of harm. Id.
 See Hansen v. SkyWest Airlines, 844 F.3d 914, 926–27 (10th Cir. 2016) (describing the use of IIED claims for sexual harassment in the workplace).
 Restatement (Second) of Torts § 46 cmt. j (Am. Law Inst. 1965); Restatement (Third) of Torts: Liability for Physical & Emotional Harm § 46 cmt. j. IIED claims also require that the defendant intended to inflict severe emotional distress or acted with reckless disregard of the likelihood of plaintiff suffering such harm. Restatement (Third) of Torts: Liability for Physical & Emotional Harm § 46 cmt. h.
 Restatement (Second) of Torts § 46 cmt. d; Restatement (Third) of Torts: Liability for Physical & Emotional Harm § 46, cmt. d.
 Restatement (Second) of Torts § 46 cmt. j.
 See Restatement (Third) of Torts: Liability For Physical & Emotional Harm § 46 cmt. j (reiterating the reasonable person standard that “the law intervenes only when the plaintiff’s emotional harm is severe and when a person of ordinary sensitivities in the same circumstances would suffer severe harm”); see also Sean O’Brien, The Highly Sensitive Person’s Redress for Intentional Infliction of Emotional Distress: Utilizing Experts in the Courtroom, 49 U. Mem. L. Rev. 533, 549 (2019) (stating that “the law remains steadfast to the standard of a reasonable person of ordinary sensitivities” in the IIED claim).
 See Kanzler v. Renner, 937 P.2d 1337, 1340–42, 1342 n.3 (Wyo. 1997) (discussing the interplay between Title VII and IIED claims in the area of sexual harassment); Catharine A. MacKinnon, Sexual Harassment of Working Women: A Case of Sex Discrimination 164–74 (1979) (describing early tort actions for sexual harassment, including claims for battery, assault, and IIED); cf. Martha Chamallas, Discrimination and Outrage: The Migration from Civil Rights to Tort Law, 48 Wm. & Mary L. Rev. 2115, 2127–35 (2007) (describing judicial reluctance to use IIED to address hostile environment sexual harassment). While this article addresses the common law claim, workplace sexual harassment can also be brought under the federal statute that addresses sex discrimination, known as “Title VII.” Title VII of the Civil Rights Act of 1964, 42 U.S.C. § 2000e-2(a) (2018). The Guidelines for the Equal Employment Opportunity Commission state that workplace discrimination based on sex is prohibited. 29 C.F.R. § 1604.11(a) (2017). Much ink has been spilled about this cause of action. The Supreme Court has found two main types of sexual harassment under Title VII: (1) quid pro quo, and (2) hostile work environment, in which the sexual conduct is so offensive and intimidating that it affects the employee’s ability to perform a job. See Meritor Sav. Bank, FSB v. Vinson, 477 U.S. 57, 65 (1986). The claimant must prove that the environment was sufficiently hostile from both an objective and subjective perspective. See Harris v. Forklift Sys., Inc., 510 U.S. 17, 21–22 (1993). An objectively hostile work environment is one that “a reasonable person would find hostile or abusive.” Id. at 21. The Supreme Court has inched toward recognizing a more subjective, gendered perspective, stating that this “reasonable person” should be viewed from the perspective of the reasonable person in the plaintiff’s position. Oncale v. Sundowner Offshore Servs., Inc., 523 U.S. 75, 81 (1998) (citing Harris, 510 U.S. at 23); see also Burlington N. & Santa Fe Ry. Co. v. White, 548 U.S. 53, 69–70 (2006) (suggesting that the consideration of how a person in the plaintiff’s position would respond is part of an objective standard).
 See Hansen v. SkyWest Airlines, 844 F.3d 914, 926–27 (10th Cir. 2016).
 Kanzler v. Renner, 937 P.2d 1337 (Wyo. 1997).
 Id. at 1343–44.
 See Robert L. Rabin, Emotional Distress in Tort Law: Themes of Constraint, 44 Wake Forest L. Rev. 1197, 1207–08 (2009).
 See Restatement (Second) of Torts § 46 cmt. d (Am. Law Inst. 1965) (“[T]he case is one in which the recitation of the facts to an average member of the community would arouse his resentment against the actor, and lead him to exclaim, ‘Outrageous!’”); see also Kanzler, 937 P.2d at 1341–42.
 See Daniel Givelber, The Right to Minimum Social Decency and the Limits of Evenhandedness: Intentional Infliction of Emotional Distress by Outrageous Conduct, 82 Colum. L. Rev. 41, 51–53 (1982); Cristina Carmody Tilley, The Tort of Outrage and Some Objectivity About Subjectivity, 12 J. Tort L. 283, 284 (2019) [hereinafter Tilley, The Tort of Outrage].
 Restatement (Third) of Torts: Liability for Physical & Emotional Harm § 46 cmt. d (Am. Law Inst. 2012). As the Restatement describes:
 Pavilon v. Kaferly, 561 N.E.2d 1245 (Ill. App. 1990).
 Id. at 1251.
 Pavlik v. Kornhaber, 761 N.E.2d 175 (Ill. App. 2001).
 Id. at 186.
 See Gregory C. Keating, Reasonableness and Rationality in Negligence Theory, 48 Stan. L. Rev. 311, 360–64 (1996); Unikel, supra note 116, at 326. This stems from the basic proposition by Thomas Hobbes and John Locke that individuals are separate and autonomous in the state of nature and cannot exercise complete freedom of action without interfering with the rights and interests of others. Unikel, supra note 116, at 348; see also Zipursky, supra note 115, at 2163 (“When we require people to be reasonable, we are requiring them to constrain their conduct by reference to its potential impact on other individuals.”).
 See Adam J. Kolber, The Experiential Future of the Law, 60 Emory L.J. 585, 588 619, 622 (2011).
 See Barbara A. Gutek et al., The Utility of the Reasonable Woman Legal Standard in Hostile Environment Sexual Harassment Cases: A Multimethod, MultiStudy Examination, 5 Psych. Pub. Pol’y & L. 596, 602–04 (1999); Kerns, supra note 24, at 217.
 Social science research suggests that women tend to see relatively more incidents and perceive greater harm from those incidents than men because “women tend to be the victims in sexual harassment encounters.” Barbara A. Gutek, Understanding Sexual Harassment at Work, 6 Notre Dame J.L. Ethics & Pub. Pol’y 335, 343 (1992).
 See Chamallas, Introduction to Feminist Legal Theory, supra note 176, at 315.
 Drawing on this research, some theorists like Professor Kathryn Abrams have argued in favor of judging workplace harassment from the perspective of a reasonable victim. See Kathryn Abrams, Gender Discrimination and the Transformation of Workplace Norms, 42 Vand. L. Rev. 1183, 1206 n.103 (1989). Abrams argues that women perceive sexual harassment differently for several reasons, including reasons based on threats to personal safety and structural reasons such as precarious positions in the workplace relative to men. Id. at 1205–09. The area of sexual harassment in the workplace has received much scholarly attention. See, e.g., Ehrenreich, supra note 150, at 1193–1201; Susan Estrich, Sex at Work, 43 Stan. L. Rev. 813, 816–26 (1991).
 Papillon argues, for example, that stress, including social stress from sexual harassment, can increase inflammation in the victim’s body and affect healing and aging. See Kimberly Papillon, The Neuroscience and Epigenetics of Sexual Harassment: Brain Reactions, Gene Expressions, and the Hostile Work Environment Cause of Action, 7 Tenn. J. Race, Gender & Soc. Just. 1, 67–68 (2018) (indicating that harassment can make the victim more vulnerable to physiologic and psychological injury). Professor Cristina Tilley suggests that neuroscience may provide objective evidence as to whether the test of outrage has been sufficiently satisfied. Tilley, The Tort of Outrage, supra note 197, at 312 (“[T]he law’s search for ‘outrageous’ behavior may be understood as a search for scientifically maladaptive aggression.”).
 See Papillon, supra note 209, at 61, 66–69 (describing how workplace microaggressions “focus[ed] on gender” can lead to negative epigenetic changes for females); Lisa Molix, Sex Differences in Cardiovascular Health: Does Sexism Influence Women’s Health?, 348 Am. J. Med. Sci. 153, 153–54 (2014); Susan H. Berg, Everyday Sexism and Posttraumatic Stress Disorder in Women: A Correlational Study, 12 Violence Against Women 970, 983–84 (2006).
 See Martha Chamallas, Discrimination and Outrage: The Migration from Civil Rights to Tort Law, 48 Wm. & Mary L. Rev. 2115, 2174–79 (2007).
 Id. at 2175–79.
 See Chamallas & Wriggins, supra note 173, at 185–87; Martha Chamallas, The Architecture of Bias: Deep Structures in Tort Law, 146 U. Pa. L. Rev. 463, 499 (1998) [hereinafter Chamallas, The Architecture of Bias] (“[L]egal claims for emotional distress have been devalued in part because they are associated with female plaintiffs.”). Professor Govind Persad has noted similar observations. See Govind Persad, Law, Science, and the Injured Mind, 67 Ala. L. Rev. 1179, 1197–98 (2016) (“[S]everal commentators have complained that the disfavoring of emotional distress torts represents an unjustified bias that is particularly disadvantageous to female plaintiffs.”).
 Chamallas, The Architecture of Bias, supra note 213, at 469. The law, under this view, fails to attach sufficient value to “caring, nurturing, empathy, and intimate human connections[,]” such as are recognized in NIED bystander claims. Chamallas & Wriggins, supra note 173, at 25.
 Id. at 25–26.
 Chamallas, The Architecture of Bias, supra note 213, at 470.
 For a fascinating review of the physiologic impact of sexual harassment in the workplace, see generally Papillon, supra note 209 (arguing that neuroscience and epigenetics can be used to accurately assess the victim’s injury and damages, as well as assess the brain reactions of the onlookers—judges, jurors, witnesses, harasser, and employers—to the harassment). Because this article focuses on man-on-woman sexual harassment, it discusses the physiologic effects of harassment on female victims. See id. at 66–69 n.14.
 We are already noting these differences with regard to the incidence of PTSD in males and females. See supra notes 34–62 and accompanying text. The emerging research on stress, the fear response, and memory processing suggest that women and men may create and retain memories of emotional material differently, which could influence how we control learned fear and anxiety and may account for differences in population rates of associated brain disorders like PTSD. See id.
 Even if courts do not use this categorical evidence to adopt a reasonable woman standard for limited application, they still could allow expert testimony to weigh the reasonableness of the emotional distress before ruling on a motion to dismiss or motion for summary judgment. See Forest v. Pawtucket Police Dep’t, 290 F. Supp. 2d 215, 232 (D.R.I. 2003) (recognizing the value of expert testimony to prove elements of an IIED claim at the summary judgment phase).
 Examples abound of stereotypical views of the female nature. Jean-Jacques Rousseau articulated it this way: “A perfect man and a perfect woman ought no more to resemble each other in mind than in features; . . . One must be active and strong, the other passive and weak. One must needs have power and will, while it suffices that the other have little power of resistance.” Jean-Jacques Rousseau, Rousseau’s Emile or Treatise on Education 260 (William H. Payne trans., D. Appleton & Co. 1918) (1762).
 See, e.g., Erica Goldberg, Emotional Duties, 47 Conn. L. Rev. 809, 842 (2015) (arguing for individual responsibility to take care of ourselves that “limits the duties others owe to avoid distressing us”).
 See Chamallas & Wriggins, supra note 173, at 190. Many scholars recognize that tort law has an expressive function. See, e.g., Cass R. Sunstein, The Expressive Function of Law, 144 U. Pa. L. Rev. 2021, 2021–22 (1996).
 See Schlanger, supra note 147, at 139 (describing how courts have “refused to hold women to a norm of timidity”).
 Professor Mayo Moran, in examining some areas of criminal law where the reasonable person standard is used (such as self-defense, provocation, and sexual assault), ultimately concluded that subjectivizing the standard will not enhance equality. Moran, supra note 111, at 202–31. Instead, she found that subjectivizing the standard in those contexts would enable perpetrators to invoke discriminatory stereotypes, which may leave judges with simple questions of credibility. As she stated, “[t]he more widely held such beliefs, the more credible they will be.” Id. at 230 (“Subjectivizing the standard, far from promoting equality, simply seems to give more unfettered play to the very beliefs that are most likely to undermine equality.”).
 Admissibility of evidence and other evidentiary questions are beyond the scope of this Article. See supra notes 112–114 and accompanying text.
 An example of this line of thinking arises in lawsuits challenging paternity leave policies that differ for men and women. See, e.g., Savignac v. Jones Day, No. 1:19-cv-02443-RDM, 2020 WL 5291980, at *5 (D.D.C. Aug. 13, 2019) (describing plaintiff’s argument that men should be given the same paternity leave as women); see also Barbara Y. Welke, Unreasonable Women: Gender and the Law of Accidental Injury, 1870–1920, 19 Law & Soc. Inquiry 370, 372 (1994) (arguing that gender shaped the development of negligence law, and legal precedents that initially favored women became available to men as well). As Professor Barbara Welke pointed out, “[a]ll passengers of railroads, for example, benefitted from the longer stops required for ladies to alight.” Id.
 In the context of antidiscrimination law, Professor Katherine Franke argues:
Katherine M. Franke, The Central Mistake of Sex Discrimination Law: The Disaggregation of Sex from Gender, 144 U. Pa. L. Rev. 1, 2–3 (1995); see also Sherrine M. Walker & Christopher D. Wall, Feminist Jurisprudence: Justice and Care, 11 B.Y.U. J. Pub. L. 255, 281 (1997) (“To listen to this feminine voice . . . would be to compound the effects of age-old male domination and reaffirm the male-induced . . . roles adopted by women.”).
 For example, societal influences like poverty and crime could also account for differences in perception and reaction to emotional harm. See Tama Leventhal & Jeanne Brooks-Gunn, Moving to Opportunity: An Experimental Study of Neighborhood Effects on Mental Health, 93 Am. J. Pub. Health 1576, 1576 (2003) (finding that a policy that moved families out of high-poverty areas had a positive effect on mental health); Amber L. Pearson & Gregory D. Breetzke, The Association Between the Fear of Crime, and Mental and Physical Wellbeing in New Zealand, 119 Soc. Indicators Rsch. 281, 289 (2014) (discussing the relationship between fear of crime and “certain physiological changes and unhealthy behavior patterns”); Kevin M. Simon, Michaela Beder & Marc W. Manseau, Addressing Poverty and Mental Illness, Psychiatric Times (June 28, 2018), https://www.psychiatrictimes.com/special-reports/addressing-poverty-and-mental-illness [https://perma.cc/77XC-N48T].
 Use of social framework evidence remains controversial. See Melissa Hart & Paul M. Secunda, A Matter of Context: Social Framework Evidence in Employment Discrimination Class Actions, 78 Fordham L. Rev. 37, 41–44 (2009) (describing the use of social framework evidence in matters such as reliability of eyewitness identification, the battered woman’s syndrome, and employment discrimination).
One unanswered question is whether—and at what point—average differences may be used in law and policy decision-making. Average differences may be used to disadvantage women as a class, or to disadvantage individual women who are not “average.” For example, if science shows that women on average are more vulnerable to PTSD than men due in large part to differences in brain structure and function, could women be removed from combat duties? Though such a decision would surely be “because of sex,” would the military be able to raise a defense that this is a bona fide occupation qualification (“BFOQ”)? How much greater would the risk have to be to qualify as a BFOQ? Should an individual woman be given the opportunity to argue that the policy is not applicable to her given her individual resiliency?
Normative views would also come into play in addressing this question. Professor Catharine MacKinnon argues that the essence of unlawful unequal treatment is not difference—men are just as different from women as women are from men—but a socially-imposed hierarchy. See Catharine A. MacKinnon, Equality, 149 Daedulus 213, 213–15 (2020) (arguing for “substantive equality”). In other words, the consequences of the difference are socially determined. Under this view, women should not be deprived of the opportunity to serve in combat and may accept the potential for the greater risk of PTSD, as men also have the potential to suffer from PTSD in combat and have been given the opportunity to assume that risk.
 See Gary T. Schwartz, Feminist Approaches to Tort Law, 2 Theoretical Inquiries L. 175, 189 (2001).
 See supra notes 176–177 and accompanying text.
 Neuroscience studies finding sex-based brain differences may have implications for other areas of tort law. For example, informed consent in the medical treatment context relies on the application of the reasonable person standard. Although the standard originally relied on the “professional” rule to determine what information on risks a medical provider needed to disclose to gain informed consent, this test has been replaced by the now-favored “patient” rule, which demands that the patient be offered information material to a reasonable person’s informed decision. See, e.g., Matthies v. Mastromonaco, 733 A.2d 456, 461–62 (N.J. 1999). The normative value underlying the test is that of individual autonomy: the patient, not the medical provider, should make the life decision about whether to undergo a particular procedure. See id. at 460. We rely on the objective reasonable person test—rather than what this particular patient would want to know—because of the complicated issue of causation. The patient would almost certainly testify (and believe) that she wanted full disclosure of all risks and would not have proceeded with the treatment if she had received it. Thus, the objective patient rule theoretically avoids the problem of bias and idiosyncrasy on the part of the patient. It also offers ease of administration: application of an individualized standard would eliminate any standard altogether. But if science can show that women and men, on average, process bodily risks differently in given situations, this would suggest that a sex-based standard is not too idiosyncratic or individualized. Instead the standard could recognize broad group differences in reactions. A blended standard of informed consent could govern a sex-based view of autonomy and bodily integrity. Cf. Chamallas, Feminist Legal Theory and Tort Law, supra note 111, at 395–96 (drawing an analogy from the medical-based informed consent doctrine to outline sufficient consent in sexual assault tort claims, which would require defendants to obtain a sexual partner’s affirmative permission to proceed or face liability). Similarly, the standard of care for treatment of brain disorders would now necessarily take into account whether the patient is male or female. For example, female athletes may be more likely to suffer concussion injury than male athletes during their career, which may be related to brain physiology differences. Tatyana Mollayeva, Graziella El-Khechen-Richandi & Angela Colantonio, Sex & Gender Considerations in Concussion Research, 3 Concussion 1, 2 (2018); Randy Dotinga, Concussions More Likely in Female Athletes, WebMD (Feb. 28, 2017), https://www.webmd.com/brain/news/20170228/concussions-more-likely-in-female-athletes [https://perma.cc/RUA8-E7LL].
 Although the law does not individualize reactions to extreme stress when these reactions are used as part of an element of duty or breach, the law individualizes injuries for damages under the eggshell plaintiff rule. Once the tortfeasor is found to have breached his duty of due care in a way that caused injury, the law holds the tortfeasor responsible for all injuries, even unusual or idiosyncratic ones. See Dobbs et al., supra note 120, § 15.11.
 Assuming the concept of a reasonable woman’s standard gains judicial acceptance, courts and litigants will need to work out various practical issues in applying the standard. Will application of the standard be case-specific, requiring the plaintiff to present expert and other proof that the standard is appropriate in her particular case? What evidence will the defendant be permitted to introduce to challenge use of the standard? Will these admissibility issues be handled outside the jury’s presence? See, e.g., Fed. R. Evid. 104. How should the jury be instructed? For example, will the jury be instructed to apply a reasonable woman’s standard to certain elements of emotional harm claims, or will they be instructed that they may consider sex-based brain differences when applying a reasonable person standard? These and other issues will all need to be considered, although they are beyond the scope of this Article.
 See Dobbs et al., supra note 120, § 10.11.
 Defendants could conceivably raise equal protection challenges to the use of a reasonable woman standard, claiming that the standard does not survive intermediate scrutiny. See, e.g., Frontiero v. Richardson, 411 U.S. 677, 682–83 (1973). While future scholarship may address this constitutional question, we can presume the same scientific evidence that shows sex-based distinctions in emotional distress responses would also be used to meet any constitutional challenge.
 See Cristina Carmody Tilley, Tort Law Inside Out, 126 Yale L.J. 1320, 1356, 1364 (2017).
 See Dobbs et al., supra note 120, § 10.12; Calnan, supra note 116, at 15 (“[L]aw’s longstanding norms are constantly mediated by judges and juries informed by prevailing social values.”); Welke, supra note 226, at 386 (explaining that an explicitly bifurcated standard of due care for men and women did not develop historically because jurors implicitly assumed that jury instructions on reasonableness reflected different community expectations of reasonable behavior for men and women).
 See Miller & Perry, supra note 122, at 367–68 (“[A]ny rule needs some content—at a minimum, some general guidelines that will enable courts to adjudicate nonarbitrarily and allow potential injurers and victims to prepare for contingencies.”).
 It is critical to enter this discussion cautiously. For example, could neuroscience research support an argument that there are sex-specific differences in cognitive abilities that implicate workplace discrimination claims? This issue, once addressed by Dr. Larry Summers to much controversy, see Scott Jaschik, What Larry Summers Said, Inside Higher Ed (Feb. 18, 2005), https://www.insidehighered.com/news/2005/02/18/what-larry-summers-said [https://perma.cc/PQP4-H3QK], resurfaced in the lawsuit brought by James Damore, a former Google software engineer. When Google fired Damore, he filed a lawsuit claiming that Google discriminates against white men with conservative views. He argued that inherent biological differences and not the lack of opportunity or prejudice explained the shortage of women in leadership and technical positions in the tech industry. Louise Matsakis, Labor Board Rules Google’s Firing of James Damore Was Legal, Wired (Feb. 16, 2018, 6:31 PM), https://www.wired.com/story/labor-board-rules-google-firing-james-damore-was-legal [https://perma.cc/HZ6A-5SY7].
 Martha Chamallas & Linda K. Kerber, Women, Mothers, and the Law of Fright: A History, 88 Mich. L. Rev. 814, 863 (1990).
 See Antonio R. Damasio, The Strange Order of Things: Life, Feelings, and the Making of Cultures 171, 243 (2018). As Professor Antonio Damasio has stated, “It is often feared that greater knowledge of biology reduces complex, minded, and willful cultural life to automated, pre-mental life[,]” but instead, advances in science “achieve something spectacularly different: a deepening of the connection between cultures and the life process[,]” and thus “reinforce the humanist project.” Id.