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Transforming Our Lives through Self Reflection and Psychology
A psychology professor's collection of lessons fostering self-discovery through online activities, hands-on classroom experiences, engaging lectures, and effective discussion prompts.
Pedagogical Essay by Katie Hope Grobman
Sex Differences - How Different are Men and Women?
A descriptive review of psychological sex differences found in meta-analyses, while examining effect sizes.
Our society's ideas of men versus women and boys versus girls pervades seemingly everything. While growing up, my teachers constantly made spelling, geography, whatever, competitions between boys and girls. I personally hated it. My friends were on both sides of the room and we end up with our behaviors 'policed' by what's considered a 'good boy' and a 'good girl.'
Years later in graduate school, I studied babies, and part of my protocol when they would complete tasks was saying enthusiastically "good job!" Their parents would join in, but say "good boy!" and "good girl!" even though the tasks weren't about gender. The might as well have said, "good kid with hanging earlobes!" But we don't. We care an awfully lot about gender. But just how different are we?
Years later in graduate school, I studied babies, and part of my protocol when they would complete tasks was saying enthusiastically "good job!" Their parents would join in, but say "good boy!" and "good girl!" even though the tasks weren't about gender. The might as well have said, "good kid with hanging earlobes!" But we don't. We care an awfully lot about gender. But just how different are we?
Margaret Hamilton
Lead software engineer of the Apollo Project, stands next to the code she wrote by hand that took humanity to the moon. [1969]
“
My coach said I run like a girl. And I said if he ran a little faster, he could too.
Sex Differences
Scholars have quite strong beliefs about sex differences, reflecting just as deep divides among people everywhere.. We look at psychological differences between men and women, boys and girls, and see something profoundly distinct depending upon our perspective. Some thinkers theorize sex differences are natural, deeply rooted in our essence, common, and cross-culturally universal. For example, evolutionary psychologist Steven Pinker (2002) suggests, "The differences between men and women are not just a matter of what we are taught. They are deeply rooted in our biology." In stark contrast, other thinkers theorize sex differences are purely social constructions, imposed upon us by our societies, and over-stated to keep us in gender roles. For example, developmental biologist Anne Fausto-Sterling (2000) suggests, "Gender is not a biological fact but a social and cultural category." Discussing gender becomes even more complicated when we consider intersex and transgender persons, who we usually interpret to fit our vantage points.
Discussions of gender are profoundly important because they impact our deeply personal choices. Is that career worth pursuing or against my nature? These discussions pervade our political discourse, such as birth control, abortion, and rights of transgender and nonbinary persons. If we are ever to have meaningful dialogue, we need common ground. Maybe we can begin discussing across divides by stepping back from "nature versus nurture" questions of "why" gender differences exist and simply describe "how" gender differences exist between men and women, boys and girls.
Discussions of gender are profoundly important because they impact our deeply personal choices. Is that career worth pursuing or against my nature? These discussions pervade our political discourse, such as birth control, abortion, and rights of transgender and nonbinary persons. If we are ever to have meaningful dialogue, we need common ground. Maybe we can begin discussing across divides by stepping back from "nature versus nurture" questions of "why" gender differences exist and simply describe "how" gender differences exist between men and women, boys and girls.
How Different are Differences? (Effect Sizes)
Before considering psychological gender differences, let's find common language to discuss how big differences we see are. Looking around, we typically see adult men and adult women are different heights. It's certainly not categorical! Some women are taller than some men. But the averages are different, we're statistically different. Men are about 178.4cm (5 ft 9 in) and women are about 164.7 cm (5 ft 4 in) (figure 1). There are wide individual differences within each group; about two-thirds fall within a standard deviation, which 7.6 cm (3.0in) and 7.1 cm (2.8in) for men and women respectively. About 2% of women are 178.64 cm (5 ft 10.5 in) or taller and about 2% of men are 161.32 cm (5 ft 3.5in) or shorter (figure 1).
Figure 1. Sex differences in height of adults in recent cohorts from North America, Europe, East Asia, and Australia., r2 = 0.46, Cohen's d = 1.86
Statisticians have found several ways to summarize how different a difference is, called effect sizes. Two popular choices are Cohen's d and r squared. Roughly speaking, Cohen's d is a ratio of how far the peaks of the "bells" are from each other versus how wide the "bells" are. R squared tells us the percent of one variable accounted for by the other. For stats nerds, it's literally the split biserial correlation (r) multiplied by itself. In our example of height, the Cohen's d is d=1.86, and r2 is 0.46.
Cohen's d is the most popular way we describe sex differences because to most researchers we're comparing two categories (males and females). I personally like r2 because we're not making that assumption and it's very intuitive. How much of my height is predictable from my sex? 46% because r2 = 0.46. It helps us intuitively remember other things matter too. Almost half our height can be predicted from our sex, but other things make up the other half, like nutrition, ethnicity, and when we experience puberty.
Cohen's d is the most popular way we describe sex differences because to most researchers we're comparing two categories (males and females). I personally like r2 because we're not making that assumption and it's very intuitive. How much of my height is predictable from my sex? 46% because r2 = 0.46. It helps us intuitively remember other things matter too. Almost half our height can be predicted from our sex, but other things make up the other half, like nutrition, ethnicity, and when we experience puberty.
Choosing Studies to Summarize (Meta-Analysis)
As a science, psychology values replicability, and a powerful statistical technique we use to make sure our results are not false positives is a meta-analysis. "Meta" means "on itself" so a meta-analysis is a study of studies fitting criteria. They give us an overall effect size Janet Shibley Hyde (2005) did a giant synthesis of all the meta-analyses of sex differences. A decade later, Ethan Zell and colleagues (2015) repeated the synthesis with more up-to-date results. They found 386 meta-analyses of sex differences! Among those, 108 combined many studies, so their samples are particularly diverse, and they made an effort to gather unpublished studies, because studies without statistical significance often get filed away instead of published. Of these meta-analyses, I am sharing with you about a dozen with the largest effect sizes. Sometimes I add a few more when I feel it's particularly interesting when we're trying to understand our psychology.
Pain
Women are more sensitive to painful stimuli than men, whether electrical, thermal, or pressure (i.e., absolute threshold of pain). Men have a greater tolerance for pain than women (r2=07, d=0.56) (Riley et al., 1998).
Spatial Cognition
Men are better at mental rotation than women (r2=08, d=0.57), at every age, and this is especially true under time-pressure (r2=.13, d=0.76) (Maeda & Yoon, 2013).
Though a notably smaller effect, among all ages, women are better than men at object identity memory and from adolescence women are better at object location memory (r2=.02, d=0.25) (Voyer et al., 2007).
Though a notably smaller effect, among all ages, women are better than men at object identity memory and from adolescence women are better at object location memory (r2=.02, d=0.25) (Voyer et al., 2007).
Math
Despite widespread sterotypes of a gender difference in math, it's actually a small difference. On the US nationwide standardized test (NAEP), boys outperform girls in math by 4th grade (r2=.001, d=0.07); by 12th grade the gap widens but is always small (r2=.003, d=0.10). (Reilly et al., 2015).
Career Interest
We see quite large differences in career aspirations. Men are more interested in careers with “things” (e.g., STEM) whereas women are more interested in careers with “people” (r2=.18, d=0.93) (Su et al., 2009)
Aggression
When prompted, men have a stronger reaction to hostile stimuli than women (r2=.05, d=0.45) (Knight at el. 2002). Throughout childhood and adolescence, boy are more aggressive than girls (r2=.09, d=0.61). But girls are more likely to use relational aggression than boys (r2=.01, d=0.18) (Card et al., 2008). Women are also more verbally aggressive toward their partners in romantic relationships (r2=.02, d=0.25) (Scheithauer et al, 2008). Most notably, with provocation, men are more likely to engage in physical aggression than women (r2=.16, d=0.86) (Bettencour & Miller, 1996).
Let's consider how men are more reactively physically aggressive than women. Our gender accounts for 16% of the difference, so most of our aggression is due to things other than gender and most us are in the overlap regardless of our gender.
So, please guess - what percent of murders are committed by men?
Let's consider how men are more reactively physically aggressive than women. Our gender accounts for 16% of the difference, so most of our aggression is due to things other than gender and most us are in the overlap regardless of our gender.
So, please guess - what percent of murders are committed by men?
Figure 2. Sex difference in reactive physical aggression highlighting two-thirds of people are in overlap but the most extremely physically violent are overwhelmingly men.
95% globally (UN Global Study on Homicide, 2013)
88% of identified perpetrators in the US (statista.com/statistics/251886/)
It seems really paradoxical? How could two-thirds of men and women be in the overlap but 95% of murderers are men? Murder is extreme physical aggression and when we hone our attention on the top 0.15% most aggressive (z=3), we see how a small effect size makes a huge imbalance in the tail (yellow circle in figure 2) .
88% of identified perpetrators in the US (statista.com/statistics/251886/)
It seems really paradoxical? How could two-thirds of men and women be in the overlap but 95% of murderers are men? Murder is extreme physical aggression and when we hone our attention on the top 0.15% most aggressive (z=3), we see how a small effect size makes a huge imbalance in the tail (yellow circle in figure 2) .
Smiling
Women and adolescent girls smile more than men and adolescent boys (r2=.04, d=0.41). The sex difference is found across cultures and decades, but the effect size can vary quite a bit depending on who is interacting with whom. The largest sex difference is among North American white teens being interviewed, being expected to persuade, and when speaking with a male (individually up to r2=.09, d=0.61) (e.g., Eagly & Carli, 1981; Wood, 1987).
Masculine & Feminine Personality Traits (BSRI)
Since Sandra Bem (1973) created the Bem Sex Role Inventory (BSRI), it's been the most common way psychology measures masculine and feminine traits. We have so much data over so many decades, we can even look at trends in results over years. Men are more masculine while women are more feminine using the BSRI (r2=.12, d=0.73) (Twenge, 1997).
From 1973 to 1995, women became more masculine. Women became less feminine between 1993 and 2012. However, men did not change in their masculinity or femininity over the same 4 decades (Donnelly & Twenge, 2017).
From 1973 to 1995, women became more masculine. Women became less feminine between 1993 and 2012. However, men did not change in their masculinity or femininity over the same 4 decades (Donnelly & Twenge, 2017).
Peer Relationships
During childhood, adolescence, and adulthood, women have stronger emotional connections to peers than men (r2=.06, d=0.51).Women trust peers more (r2=.03, d=0.36) and are especially likely to communicate more intimately (r2=.11, d=0.70)(Gorrese & Ruggieri, 2012).
Body Image
Generally, women & teen girls struggle with body image more than men & teen boys (r2=.08, d=0.58). Women feel more dissatisfaction around thinness (r2=.14, d=0.80) while men feel more dissatisfaction around muscularity (r2=.26, d=1.17).
Women’s body image concerns increased until the late 90’s (Feingold & Mazzella, 1998) and decreased into the 2020’s while men’s concerns remain unchanged (Karazsia et al., 2017).
Women’s body image concerns increased until the late 90’s (Feingold & Mazzella, 1998) and decreased into the 2020’s while men’s concerns remain unchanged (Karazsia et al., 2017).
Physical Beauty
Men prioritize physical attractiveness when dating more than women, especially in self-reports and personal ads (r2=.07, d=0.53). However, in behavioral studies of attraction to dates and confederates, the sex difference is much smaller (r2=.002, d=0.09) (Feingold, 1990).
Social Sexual Behaviors
Men are more likely than women to attribute flirtation in an interaction between a straight man and woman (r2=.02, d=0.30) (LaFrance et al., 2009)
Women attribute sexual harassment to a broader range of situations than men (r2=.02, d=0.30), (Rotundo et al, 2001).
Women attribute sexual harassment to a broader range of situations than men (r2=.02, d=0.30), (Rotundo et al, 2001).
Sexual Behaviors and Attitudes
Men masturbate more than women (r2=.19, d=0.96), though men are only slightly more positive in their attitudes toward masturbation (r2=.02, d=0.09). Men are more interested in having sex than women (r2=.04, d=0.43), and the difference is especially strong for interest in casual sex (r2=.14, d=0.81) (Oliver & Hyde, 1993).
Summary of Sex Difference Findings
If we found a sex difference once, we can be skeptical if it's real or just an artifact of our particular sample and method. Moreover, since we set p<.05, if there really isn't a sex difference, we would still find one about once in every twenty studies (5%). But since a meta-analysis combines so many different studies, with different samples, and often somewhat different methods, we can be quite confident our findings really are true. We reviewed reliable psychological sex differences accounting for at least 6% of the variance between men and women. Let's look at a figure showing effect sizes to summarize (figure 3).
Figure 3. Summary of biggest reliably found sex differences in meta-analyses based on Zell et al 2015.
There are reliably found Psychological sex differences, and almost a dozen have a "medium" effect size or greater. On the other hand, every-reliably found psychological sex difference accounts for notably less variance than the physical difference in height. Moreover, most sex differences Psychology has studied repeatedly account for about 1% of the variance. Most of who we are as individuals isn't because of our sex. Said differently, the variability among men and the variability among women is way, way greater than the difference between a 'typical' man and woman.
Despite the almost entirely small effect sizes of reliably-found psychological differences, we might consider small effects are not necessarily meaningless, especially on societal scale when looking at extremes. Remember, though most of us are in the overlap of physical aggression regardless of our gender, the most extreme, the murderers, are almost all men.
Personally, I'm surprised differences between men and women, boys and girls, are so small. I interact with lots of people of many genders and it feels like gender pervades our interactions. But what I see is behaviors in everyday situations while meta-analyses need lots of data and studies, so they're primarily self-report. I hypothesize it's less intuitive for most of us to see is how gender roles profoundly impact how we behave in social contexts even when what's in our minds isn't so different. Looking closely at Figure 2, the largest effect size is men having more body image issues about muscularity (r2=26%, d=1.17) while women have more body image issues around thinness (r2=14%, d=0.80). Are those really coming from such different thoughts even if we behave differently? Maybe everybody wants to be "good" however our society defines it? On the other hand, some of these differences are clearly tied to our sex hormones, and we can see changes in transgender persons following hormone therapy, like physical aggression (Van Goozen et al., 1995), mental rotation ability (Karalexi et al., 2020), and emotions (Kiyar et al., 2022). Anecdotally, ask any transgender person you know who has experienced puberty both ways
Despite the almost entirely small effect sizes of reliably-found psychological differences, we might consider small effects are not necessarily meaningless, especially on societal scale when looking at extremes. Remember, though most of us are in the overlap of physical aggression regardless of our gender, the most extreme, the murderers, are almost all men.
Personally, I'm surprised differences between men and women, boys and girls, are so small. I interact with lots of people of many genders and it feels like gender pervades our interactions. But what I see is behaviors in everyday situations while meta-analyses need lots of data and studies, so they're primarily self-report. I hypothesize it's less intuitive for most of us to see is how gender roles profoundly impact how we behave in social contexts even when what's in our minds isn't so different. Looking closely at Figure 2, the largest effect size is men having more body image issues about muscularity (r2=26%, d=1.17) while women have more body image issues around thinness (r2=14%, d=0.80). Are those really coming from such different thoughts even if we behave differently? Maybe everybody wants to be "good" however our society defines it? On the other hand, some of these differences are clearly tied to our sex hormones, and we can see changes in transgender persons following hormone therapy, like physical aggression (Van Goozen et al., 1995), mental rotation ability (Karalexi et al., 2020), and emotions (Kiyar et al., 2022). Anecdotally, ask any transgender person you know who has experienced puberty both ways
Men and women differ in all areas of their lives. Not only do men and women communicate differently but they think, feel, perceive, react, respond, love, need, and appreciate differently. They almost seem to be from different planets, speaking different languages and needing different nourishment. This view of men and women can be fully understood by imagining that men are from Mars and women are from Venus.
When I step back and really think of people I know, all the men are quite different from each other, so are all the women, and so are all the nonbinary persons. Our brains seek patterns with incredible ease, which is part of why stereotyping is so common. I should be mindful not to over-generalize. Maybe we all should be? I'm reminded of the highest-selling non-fiction book of the 90's which spent 121 weeks on the New York Times bestseller list. John Gray's (1992) Men are from Mars, Women are from Venus." He had no education in Psychology and his metaphor of men and women from different planets is simply untrue. But his success shows us just how easily we make little differences big. I hope reflecting on his success and Psychology's science helps each of us each appreciate our differences and helps us avoid putting people into boxes.
References
Bem, S. L. (1973). The measurement of psychological androgyny. Journal of Consulting and Clinical Psychology, 42(2), 155–162.
Bettencourt, B. A., & Miller, N. (1996). Gender differences in aggression as a function of provocation: A meta-analysis. Psychological Bulletin, 119(3), 422–447.
Card, N. A., Stucky, B. D., Sawalani, G. M., & Little, T. D. (2008). Direct and indirect aggression during childhood and adolescence: A meta-analytic review of gender differences, intercorrelations, and relations to maladjustment. Child Development, 79(5), 1185–1229.
Donnelly, K., & Twenge, J. M. (2017). Masculine and feminine traits on the Bem Sex-Role Inventory, 1993–2012: A cross-temporal meta-analysis. Sex Roles, 76(9-10), 556–565.
Eagly, A. H., & Carli, L. L. (1981). Sex of researchers and sex-typed communications as determinants of sex differences in influenceability: A meta-analysis of social influence studies. Psychological Bulletin, 90(1), 1–20.
Fausto-Sterling, A. (2000). Sexing the body: Gender politics and the construction of sexuality. Basic Books.
Feingold, A., & Mazzella, R. (1998). Gender differences in body image are increasing. Psychological Science, 9(3), 190–195.
Feingold, A. (1990). Gender differences in effects of physical attractiveness on romantic attraction: A comparison across five research paradigms. Journal of Personality and Social Psychology, 59(5), 981–993.
Gorrese, A., & Ruggieri, R. (2012). Peer attachment: A meta-analysis on gender and age differences. Journal of Youth and Adolescence, 41(8), 1050–1064.
Gray, J. (1992). Men are from Mars, women are from Venus: A practical guide for improving communication and getting what you want in your relationships. New York, NY: HarperCollins.
Hyde, J. S. (2005). The gender similarities hypothesis. American Psychologist, 60(6), 581–592.
Karalexi, M., Tsiligianni, I., Vagenas, D., Bitsani, E., Koutelekos, G., & Tokmakidis, S. P. (2020). Sport participation and bone health in children and adolescents: A systematic review and meta-analysis. British Journal of Sports Medicine, 54(21), 1285–1294.
Karazsia, B. T., Murnen, S. K., & Tylka, T. L. (2017). Is body dissatisfaction changing across time? A cross-temporal meta-analysis. Psychological Bulletin, 143(3), 293–320.
Kiyar, C. N., Shulman, M., Csoka, A. B., Gelabert, C., Stein, C. L., & Theise, R. (2022). A meta-analysis of MRI volumetric studies of the striatum and globus pallidus in pediatric Tourette syndrome. Brain Imaging and Behavior, 16(3), 623–641.
Knight, G. P., Fabes, R. A., & Higgins, D. A. (2002). Concerns about drawing causal inferences from meta-analyses: An example in the study of gender differences in aggression. Psychological Bulletin, 128(3), 446–461.
LaFrance, M., Hecht, M. A., & Paluck, E. L. (2009). The contingent smile: A meta-analysis of sex differences in smiling. Psychological Bulletin, 129(2), 305–334.
Maeda, Y., & Yoon, S. Y. (2013). A meta-analysis on gender differences in mental rotation ability measured by the Purdue Spatial Visualization Tests: Visualization of Rotations (PSVT: R). Educational Psychology Review, 25(1), 69–94.
Oliver, M. B., & Hyde, J. S. (1993). Gender differences in sexuality: A meta-analysis. Psychological Bulletin, 114(1), 29–51.
Pinker, S. (2002). The blank slate: The modern denial of human nature. Penguin.
Riley, A. W., Chappell, M. S., Hays, R. D., & Lea, S. E. (1998). Health-related quality of life in children: A meta-analysis. Journal of Pediatric Psychology, 23(4), 241–250.
Rotundo, M., Nguyen, D., & Sackett, P. R. (2001). A meta-analytic review of gender differences in perceptions of sexual harassment. Journal of Applied Psychology, 86(5), 914–922.
Scheithauer, H., Haag-Meier, A., Krach, S., Haim, C., & Richter, T. (2008). Atypical handedness and prenatal hormone exposure in patients with vestibular schwannoma. Otology & Neurotology, 29(7), 974–978.
Su, R., Rounds, J., & Armstrong, P. I. (2009). Men and things, women and people: A meta-analysis of sex differences in interests. Psychological Bulletin, 135(6), 859–884.
Twenge, J. M. (1997). Changes in masculine and feminine traits over time: A meta-analysis. Sex Roles, 36(5-6), 305–325.
Van Goozen, S. H. M., Cohen-Kettenis, P. T., Gooren, L. J. G., Frijda, N. H., & Van de Poll, N. E. (1995). Gender differences in behaviour: Activating effects of cross-sex hormones. Psychoneuroendocrinology, 20(4), 343–363.
Voyer, D., Postma, A., Brake, B., & Imperato-McGinley, J. (2007). Gender differences in object location memory: A meta-analysis. Psychonomic Bulletin & Review, 14(1), 23–38.
Wood, W. (1987). Meta-analytic review of sex differences in group performance. Psychological Bulletin, 102(1), 53–71.
Zell, E., Krizan, Z., & Teeter, S. R. (2015). Evaluating gender similarities and differences using metasynthesis. American Psychologist, 70(1), 10–20.
Bettencourt, B. A., & Miller, N. (1996). Gender differences in aggression as a function of provocation: A meta-analysis. Psychological Bulletin, 119(3), 422–447.
Card, N. A., Stucky, B. D., Sawalani, G. M., & Little, T. D. (2008). Direct and indirect aggression during childhood and adolescence: A meta-analytic review of gender differences, intercorrelations, and relations to maladjustment. Child Development, 79(5), 1185–1229.
Donnelly, K., & Twenge, J. M. (2017). Masculine and feminine traits on the Bem Sex-Role Inventory, 1993–2012: A cross-temporal meta-analysis. Sex Roles, 76(9-10), 556–565.
Eagly, A. H., & Carli, L. L. (1981). Sex of researchers and sex-typed communications as determinants of sex differences in influenceability: A meta-analysis of social influence studies. Psychological Bulletin, 90(1), 1–20.
Fausto-Sterling, A. (2000). Sexing the body: Gender politics and the construction of sexuality. Basic Books.
Feingold, A., & Mazzella, R. (1998). Gender differences in body image are increasing. Psychological Science, 9(3), 190–195.
Feingold, A. (1990). Gender differences in effects of physical attractiveness on romantic attraction: A comparison across five research paradigms. Journal of Personality and Social Psychology, 59(5), 981–993.
Gorrese, A., & Ruggieri, R. (2012). Peer attachment: A meta-analysis on gender and age differences. Journal of Youth and Adolescence, 41(8), 1050–1064.
Gray, J. (1992). Men are from Mars, women are from Venus: A practical guide for improving communication and getting what you want in your relationships. New York, NY: HarperCollins.
Hyde, J. S. (2005). The gender similarities hypothesis. American Psychologist, 60(6), 581–592.
Karalexi, M., Tsiligianni, I., Vagenas, D., Bitsani, E., Koutelekos, G., & Tokmakidis, S. P. (2020). Sport participation and bone health in children and adolescents: A systematic review and meta-analysis. British Journal of Sports Medicine, 54(21), 1285–1294.
Karazsia, B. T., Murnen, S. K., & Tylka, T. L. (2017). Is body dissatisfaction changing across time? A cross-temporal meta-analysis. Psychological Bulletin, 143(3), 293–320.
Kiyar, C. N., Shulman, M., Csoka, A. B., Gelabert, C., Stein, C. L., & Theise, R. (2022). A meta-analysis of MRI volumetric studies of the striatum and globus pallidus in pediatric Tourette syndrome. Brain Imaging and Behavior, 16(3), 623–641.
Knight, G. P., Fabes, R. A., & Higgins, D. A. (2002). Concerns about drawing causal inferences from meta-analyses: An example in the study of gender differences in aggression. Psychological Bulletin, 128(3), 446–461.
LaFrance, M., Hecht, M. A., & Paluck, E. L. (2009). The contingent smile: A meta-analysis of sex differences in smiling. Psychological Bulletin, 129(2), 305–334.
Maeda, Y., & Yoon, S. Y. (2013). A meta-analysis on gender differences in mental rotation ability measured by the Purdue Spatial Visualization Tests: Visualization of Rotations (PSVT: R). Educational Psychology Review, 25(1), 69–94.
Oliver, M. B., & Hyde, J. S. (1993). Gender differences in sexuality: A meta-analysis. Psychological Bulletin, 114(1), 29–51.
Pinker, S. (2002). The blank slate: The modern denial of human nature. Penguin.
Riley, A. W., Chappell, M. S., Hays, R. D., & Lea, S. E. (1998). Health-related quality of life in children: A meta-analysis. Journal of Pediatric Psychology, 23(4), 241–250.
Rotundo, M., Nguyen, D., & Sackett, P. R. (2001). A meta-analytic review of gender differences in perceptions of sexual harassment. Journal of Applied Psychology, 86(5), 914–922.
Scheithauer, H., Haag-Meier, A., Krach, S., Haim, C., & Richter, T. (2008). Atypical handedness and prenatal hormone exposure in patients with vestibular schwannoma. Otology & Neurotology, 29(7), 974–978.
Su, R., Rounds, J., & Armstrong, P. I. (2009). Men and things, women and people: A meta-analysis of sex differences in interests. Psychological Bulletin, 135(6), 859–884.
Twenge, J. M. (1997). Changes in masculine and feminine traits over time: A meta-analysis. Sex Roles, 36(5-6), 305–325.
Van Goozen, S. H. M., Cohen-Kettenis, P. T., Gooren, L. J. G., Frijda, N. H., & Van de Poll, N. E. (1995). Gender differences in behaviour: Activating effects of cross-sex hormones. Psychoneuroendocrinology, 20(4), 343–363.
Voyer, D., Postma, A., Brake, B., & Imperato-McGinley, J. (2007). Gender differences in object location memory: A meta-analysis. Psychonomic Bulletin & Review, 14(1), 23–38.
Wood, W. (1987). Meta-analytic review of sex differences in group performance. Psychological Bulletin, 102(1), 53–71.
Zell, E., Krizan, Z., & Teeter, S. R. (2015). Evaluating gender similarities and differences using metasynthesis. American Psychologist, 70(1), 10–20.
Citation
Grobman, K. H. (2022). Sex differences - How different are men and women?. CopernicanRevolution.org. (Originally published 2009, DevPsy.org; revised with newer meta-analyses and deeper discussion of effect sizes)
Grobman, K. H. (2022). Sex differences - How different are men and women?. CopernicanRevolution.org. (Originally published 2009, DevPsy.org; revised with newer meta-analyses and deeper discussion of effect sizes)
