Diversity VI: Normal discrimination

As a final follow-up to my previous post on the issue of enforced diversity in the workplace, I wish to expand on the criticism that I gave on those scientists who deny the notion that biology has an influence on the different roles of men and women in society. The main argument that is given by these scientists is that the biological differences between the sexes, while existing, are smaller than is generally assumed. From this notion they derive that, based on biology, you should see only small differences between behaviors of men and women. Since this is not what can be observed, they conclude that men and women are treated differently because of (only) cultural influences.

These scientists do not understand the normal distribution.

We may assume that most characteristics of men and women, both physical and mental, are approximately normally distributed. For the sake of argument, let’s say that due to biological causes, men on average have a slightly higher aptitude for abstract thought than women, while women on average have a slightly better social sense than men. If you then give a large bunch of men and women an IQ test (which measures abstract thinking) and an EQ test (which measures social thinking), then perhaps on average men have an IQ of 100.5 and women an IQ of 99.5, while men on average have an EQ of 99.5 and women an EQ of 100.5 (I am pulling these numbers out of thin air, they are just examples). The 1-point difference shouldn’t be noticeable in everyday behavior.

However, the 1-point difference is for the average. At the extremes of the normal distribution, the differences are much more noticeable. If the shapes of the Bell curves for men and women are the same, but with a difference of 1 point for the averages, and we look at the 5% highest scorers for both groups, the average of them differs a lot more. Looking at it in another way, if you are only checking those with an IQ or EQ higher than 150, the 1-point difference for the average can easily translate to 80% of the people with an IQ higher than 150 being men, and 80% of the people with an EQ higher than 150 being women.

The fact that companies and institutions want to hire “the best” for crucial positions, entails that they discriminate to look for the high-end tail of the Bell curve which describes the population distribution for the traits which they need the most. Even if on average there is little difference between the aptitudes of men and women to do particular jobs, when you discriminate to get the best, you will generally end up with a severely skewed distribution of the sexes.

This effect is magnified by the fact that for many traits, the variance differs for the sexes. In particular, it has been reported that men tend to have a higher variance than women. This means that men fit a flatter Bell curve than women for many traits, which translates to there being a denser population of men at both extremes, even if there is no difference between the averages. In layman’s terms: if in a particular area there are more genius men than genius women, then this is offset by there being more moronic men than moronic women (though there will, of course, still be both genius women as well as moronic women).

Even if the aptitudes of men and women for a particular job are the same, fitting the exact same Bell curve, then there is still the fact that the interest for them to do that job may differ. Again, if interest in tech is normally distributed over the population, and there is on average little difference between the interests of men and women for tech (which might be the case: most people are not really interested in tech jobs), then you might still find big differences between the number of men and the number of women who are highly interested in tech, i.e., whose interest is at the high end of the Bell curve. Which means that even if women are equally able to do a tech job, that does not mean that you will find many women actually preferring to do it over some other job.

Note that the same may be noticed in high-end jobs which see a dominance of women, such as medical specialists. At a time when few women entered the job market, physicians were usually male. Nowadays, when about 40% of jobs are held by women, physicians are predominantly female — either because being a physician requires a skill set for which the best candidates tend to be women, or because it is a job that women have, on average, a higher preference for than men. Regardless, being a physician is a high-end profession where women rule — which makes mincemeat of the notion that some kind of male oppression is keeping women out of high-end jobs.

Enforcing an equal distribution of the sexes for those positions for which high skills and/or high motivation are needed, leads to either lowering the quality of how the work is done, or appointing people who would rather be doing something else.

By the way, the discussion above does not mean that there actually are only small biological differences between the sexes. In my previous post I gave three reasons to suspect that the biological differences are quite significant. However, even if you assume that there are only small biological differences between men and women, distribution of the sexes in high-end jobs will usually be unbalanced.


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