Recently a Google engineer was fired for writing a very long memo about gender differences and its implications for company diversity policy. There was an uproar and he got fired. This post addresses the author's point that, on average, men and women are different psychologically and these differences are, in part, biological.

From Google’s CEO Sundar Pichai:

The memo has clearly impacted our co-workers, some of whom are hurting and feel judged based on their gender. Our co-workers shouldn’t have to worry that each time they open their mouths to speak in a meeting, they have to prove that they are not like the memo states, being “agreeable” rather than “assertive,” showing a “lower stress tolerance,” or being “neurotic.”

From the Diversity Memo itself:

On average, men and women biologically differ in many ways. These differences aren’t just socially constructed...Women, on average, have more:

Openness directed towards feelings and aesthetics rather than ideas...a stronger interest in people rather than things, relative to men (...empathizing vs. systemizing)...

Extraversion expressed as gregariousness rather than assertiveness.

Also, higher agreeableness.

Neuroticism (higher anxiety, lower stress tolerance)

[Men have] a higher drive for status.

Okay, so the Diversity Memo's author says that, on average, women are more open, people-oriented, gregarious, anxious, and agreeable than men and men are more thing-oriented, systemizing, assertive, and status-driven. He further notes that biology accounts only partly for these gender differences, many of which are small, and there is considerable overlap between men and women. In other words, lots of men are open, people-oriented, agreeable, and anxious and plenty of women are assertive and status-driven.

Is there any truth to the author's assertions about female and male personality differences? Probably. Just go to Google Scholar and you'll find hundreds of studies and meta-analyses supporting his contentions. A few examples:

Baron-Cohen, S., J. Richler, et al. (2003). "The systemizing quotient: an investigation of adults with Asperger syndrome or high–functioning autism, and normal sex differences."

Collaer, M. L., & Hines, M. (1995). “Human behavioral sex differences: A role for gonadal hormones during early development?”

Costa, P. T., Jr., Terracciano, A., & McCrae, R. R. (2001). "Gender differences in personality traits across cultures: Robust and surprising findings.”

Feingold, A. (1994). “Gender differences in personality: A meta-analysis.”

Hyde, J. S. (2014). "Gender Similarities and Differences."

Lynn, R. and T. Martin (1997). "Gender Differences in Extraversion, Neuroticism, and Psychoticism in 37 Nations."

Miller, D. I. and D. F. Halpern (2014). "The new science of cognitive sex differences."

Schulte-Rüther, M., H. J. Markowitsch, et al. (2008). "Gender differences in brain networks supporting empathy."

The mere fact of gender differences in personality is well established. The biology of these differences is not so well established. There is, however, general agreement within the research community that biology plays a role in personality, which is not the same thing as saying biology determines personality. We're talking complex interactions, lots of mediators and moderators.

Researchers continue to disagree about the importance of biology to gender differences in personality, as well as the explanatory power of evolutionary psychology. They disagree, so they propose and test alternative hypotheses. They don't tell each other to shut up. They don't try to prevent further research because some people might feel harmed by potential findings.

If some people do feel harmed by the proposition that gender differences in personality are fairly consistently found in large samples and there is some evidence biology plays at least a small role in these differences, I suggest an education campaign, not a smear campaign.

Next: Delving into "on average" and its implications.

References:

Baron-Cohen, S., J. Richler, et al. (2003). "The systemizing quotient: an investigation of adults with Asperger syndrome or high–functioning autism, and normal sex differences." Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 358(1430): 361-374.

Collaer, M. L., & Hines, M. (1995). Human behavioral sex differences: A role for gonadal hormones during early development? Psychological Bulletin, 118(1), 55-107. http://dx.doi.org/10.1037/0033-2909.118.1.55

Costa, P. T., Jr., Terracciano, A., & McCrae, R. R. (2001). Gender differences in personality traits across cultures: Robust and surprising findings. Journal of Personality and Social Psychology, 81(2), 322-331. http://dx.doi.org/10.1037/0022-3514.81.2.322

Feingold, A. (1994). Gender differences in personality: A meta-analysis. Psychological Bulletin, 116(3), 429-456.  http://dx.doi.org/10.1037/0033-2909.116.3.429

Hyde, J. S. (2014). "Gender Similarities and Differences." Annual Review of Psychology 65(1): 373-398.

Lynn, R. and T. Martin (1997). "Gender Differences in Extraversion, Neuroticism, and Psychoticism in 37 Nations." The Journal of Social Psychology 137(3): 369-373.

Miller, D. I. and D. F. Halpern (2014). "The new science of cognitive sex differences." Trends in Cognitive Sciences 18(1): 37-45.

Schulte-Rüther, M., H. J. Markowitsch, et al. (2008). "Gender differences in brain networks supporting empathy." NeuroImage 42(1): 393-403.

Schmitt, D. P., Realo, A., Voracek, M., & Allik, J. (2008). Why can’t a man be more like a woman? Sex differences in Big Five personality traits across 55 cultures. Journal of Personality and Social Psychology,94, 168–182.

Tian L, WangJ, YanC,  He,Y.(2011) “Hemisphere- and gender-related differences in small-world brain networks: a resting-state functional MRI study”, Neuroimage, vol. 54: 191-202.