Monday, June 01, 2009

Importance of genes made a little clearer by children

Given that the Big 5 personality traits are 50% hereditable, it is discouraging to find that three in four people believe experience, rather than genes, is the primary determinant of a person's personality. That acknowledged, the naturist majority's dominance is not of equal strength across the board. Women are more inclined than men are to place importance on genes. One likely reason for this is that women pay more attention to children than men do.

Breaking down the question on personality by fertility lends credence to this assertion. The first kid forces parents to come to the realization that the way little Hayden turns out is not something they have complete control over (if much at all). Subsequent children show, through countless contrasts with their other siblings, that from the same nest very different rugrats scurry forth. The following table shows how fertility influences perceptions in this area. The percentage of women who believe genes play a primary role in determining personality by number of children (N = 1222):


While it's easier to hold quixotic notions of human nature in youth than it is after decades of staring reality in the face, this is not merely the result of younger people tending to put more emphasis on environmental factors than old codgers do (although that would still make sense in this 'theoretical framework', since younger girls are less likely to have had children than their mother's friends are). The same pattern holds across age groups. Among women between the ages of 18 and 35, 16.8% of those with no children emphasize genes, 18.4% with one child do, and 25.0% of those with two or more kids do.

Because men are less selective of their mates than women are, it's not surprising they are also less attuned to genetic influences on personality than women. Further, men rightly feel they have more individual influence over their objective desirability in the eyes of the opposite sex than women do. But fathering causes men to be more perceptive of innate differences in people as well. The percentage of men who believe genes play a primary role in determining personality by number of children (N = 1074):


GSS variables used: GENEEXPS, GENDER(1)(2), CHILDS(0)(1)(2-8), AGE(18-35)


Soul Searcher said...

Obvious confounding variable: The number of children a father chooses to have may affect his predisposition to a hereditarian position on personality.

Stopped Clock said...

Also, although I agree with you that the age of the mother, independent of the number of their children, probably contributes little to the emphasis they place on nature/nurture, I would say that you didn't really disprove it by breaking out the age brackets, since 18-35 is quite a wide range, and I expect that most of the women with 0 children are closer to 18 while most of the women with 2 or more children are close to 35.

Anonymous said...

You need to worry about reverse causality. I personally believe that genes and culture matter the most, and it does kids no harm to have lots of siblings and little attention. As a direct result, I am choosing to have a large family. After all, if nurture is useless, then the only way to get a kid you like is to have lots of them.

Anonymous said...

Eric Hoffer once said, "When people are free to do as they please, they usually imitate one another."

Isn't culture just the product of such imitation? And isn't the need to imitate an innate quality of humans and other primates? Isn't culture merely the product of our expressed genes?

Therefore genes hold culture on a leash.

OneSTDV said...

While I believe HBD is of immense importance for policy, it may sometimes be negative stimulus in family life.

Do we really want our parents to not try their hardest because they have faith genetics will just take care of it?

I think being cognizant of genetics can make some parents lazy or have a defeatist attitude.

Audacious Epigone said...


Good point. The direction the causality arrow is pointing is speculative.


Sample sizes are too small, especially among those who have children, among the 18-25 or so range. For women, it's 16.2% at 0 kids, 14.8% at 1, and 25.7% at 2+. Again, just suggestive, by no means definitive.


Your reasoning sounds impeccable to me! Get 'er done :)


In the 10000 Year Explosion, one of the major points made is disparate environments (including social culture) shape evolutionary pressures in disparate ways, but the feedback surely runs in the other direction as well. For example, the cultural dominance of men in math and science is in large part a result of women's innate relative lack of interest in them.


I struggle with the same question. In a sense, it's a modern equivalent of Pascal's Wager.

agnostic said...

"Hayden" lol.

I think you and I are the only ones for whom that name doesn't sound bizarre. Others would've used "Johnny" or "Susie."

Anonymous said...


Parents will try nonetheless to influence their children, no matter what they personally believe about genetic determination.

Understanding your child's innate personality and abilities will help you understand why you were influential or not and why he/she did not turn out exactly as you had wanted.

silly girl said...

This seems like it would lend itself to checking how much a person thinks genes affect a child's personality against how the respondent scored on wordsum.

I say this because I saw a poll of Americans in which 25% believed that the gov't had its own money vs. 75% who thought the gov't collected $ from taxpayers. It would have been interesting to see the wordsum scores for that 25%.

You would hope intelligent people would believe their own eyes when it comes to their own kids.

David said...

Fascinating post - thank you.

Audacious Epigone said...


I shared that hope, but I didn't find much evidence for it. On average, those who put primacy on experience are modestly more intelligent than those who feel genes are largely responsible.