19 August 2012

Men and women: Mars and Venus all right

Those were the days! In grandma's time, cute images such as these were standard, and no one bothered to denounce them as stereotypes. Offended by the view? According to PDC (Politically Correct Dogma), you should. According to 2012 science, you shouldn't. 

As everybody knows —child, adolescent, adult, male or female— men and women are very different creatures. Modern negationism claims that the differences observed are mainly due to society (Western society in the first place), which forces girls and boys into a behaviour which is by no means innate. Many academics prosper on gathering evidence for this view, and nowadays no decent university can afford not to have a Women's Studies department. (I remember I couldn't make sense of that word when I first heard it. What on earth were Women's Studies?)

In short, differences between men and women are lies to be exposed. No, wait! Everybody seems to agree that in matters of sexuality and aggression, men and women are different, men being the bad guys. That women are sensitive and warm, men emotionally stable and conscious of rules, these are lies to be exposed. Well, a broad study, published in 2012, found otherwise. Not to burn myself on this sensible topic, let me quote from the summary given by Skeptical Inquirer (Kenneth W. Krause, Gender Personality Differences: Planets or P.O. Boxes, Evidence or Ideology? vol. 36 no. 3, May/June 2012, 26-28.)

Having subjected a sample of 10,261 American men and women between age fifteen and ninety-two to an assessment of multiple personality variables, Del Giudice [the paper's main author] obtained results he and his team described as "striking." The "true extent of sex differences in human personality," he argued, "has been consistently underestimated." (...) When properly measured, he reports, gender personality differences are "large" and "robust." Indeed, roughly 82 percent of his cohort delivered personality profiles that could not be matched with any member of the opposite sex. (p.26)

Needless to say, these findings were not universally acclaimed. Janet Hyde, professor of psychology and women's studies, compared the gender gap to nothing more than "the distance between North Dakota and South Dakota". She's best known for her Gender Similarities Hypothesis:

males and females are similar on most, but not all, psychological variables
(Skeptical Inquirer p.26)

(The "exceptional differences" are sexuality and aggression, mentioned above.) Her own methods, so I understand, are coarser than the new ones. According to psychology professor Richard Lippa, her (averaging) method would probably lead to the conclusion that men and women have similar bodies, while Del Giudice's method would probably generate the much more intuitive conclusion that "sex differences in human body shape are quite large, with men and women having distinct multivariate distributions that overlap very little." (Skeptical Inquirer p.27)

If you are into statistics and/or psychology, you can read all of Del Giudice e.a. here. For the others, a few quotes will have to do.

Finding large overall differences [as is the case] would tell us that the sexes differ broadly in their emotional and behavioral patterns, rather than just in a few (and comparatively narrow) motivational domains such as aggression and sexuality. (p.1)

In univariate terms, the largest differences between the sexes were found in Sensitivity, Warmth, and Apprehension (higher in females), and Emotional stability, Dominance, Rule-consciousness, and Vigilance (higher in males).

The multivariate effect for latent variables (...) is an extremely large effect, corresponding to an overlap of only 10% between the male and female distributions (assuming normality). (p.4)

P.S. As statistical truths go: for an individual quantum particle or for an individual man or woman, they imply nothing.