Charles Murray

ches, so d equals –5.4 ÷ 2.9, which works out to an effect size of –1.86. This is an extremely large effect size. Most sex differences are much smaller and the distributions have much more overlap.
Note that the sign of d (negative

I also disagree with Hyde’s position that Type I errors should still be more feared than Type II errors.

We continue to learn more about the two groups. We learn that one group is more prudent, the other more happy-go-lucky; one group is more practical, the other more imaginative; and so on. In some cases, the additional traits on which the groups differ are so closely related that the new knowledge adds only a small amount to the difference; in other cases, the new information adds a lot to the degree of their difference