As one might expect, the piece that I co-authored with Brian Boutwell, Heritability and why Parents (but not Parenting) Matter, has stirred up some irritation and even anger. Part of this is simply due to the mildly hyperbolic nature of the title. Obviously on some level parents matter a great deal. What we were attempting to get at though is that most parents have far less precise control of the outcomes of their children than they think they do (you do have great control if you beat or starve your children though!). The lack of control is one reason siblings vary so much.

To make it concrete, imagine across the population variation of personality is 30% heritable, 15% accounted for by shared environment, and 55% explained by non-shared environment. The parental effect is captured in the shared environment. When behavior geneticists downplay the role of parents in affecting outcomes, they are doing so because of this value. In this example the proportion explained by the parents’ genetic variation is twice as large as the conscious environmental choices. But, note that most of the variation is not necessarily due to genetic factors!

What is this variation? The short answer is that we don’t know. One hypothesis, promoted by Judith Rich Harris in The Nurture Assumption, is that it is one’s social milieu. That is, peer groups. To my knowledge in the past 15 years there has not been much support for this thesis, suggesting to me that we’re still at a loss to explain non-shared environment. In fact it may just be an intractable stochastic aspect of life outcomes (or if you want to reduce it to biology, developmental stochasticity).

People become uncomfortable with these statistics because they suggest that the most immediate personal control you can have on the character of your offspring is through the spouse you select. Your spouse (or you) may change values over time, but you are not going to change your genes. This is not very congenial with the modern American conservative orthodoxy that crystallized after World War 2 which placed the nuclear family at the center of the culture (basically, fusionism). The rise of “family values” as inoculation against liberal permissiveness is to a great extent predicated on the idea that shared environment is very powerful over the long term. The data just don’t support this proposition.

We can see this when you look through recent history. Some of the response to the Quillette piece emphasized and reiterated that we missed something when we ignore and dismiss the importance of values that parents’ instill in their children. But values are malleable. A whole generation of Southerners grew up in the 1950s and 1960s with racial values taught to them by their parents, and they also grew out of those values as a generational cohort. Or, look what’s happening with gay marriage: …Evangelicals Are Changing Their Minds on Gay Marriage:

The shift is especially visible among young evangelicals under age 35, a near majority of whom now support same-sex marriage. And gay student organizations have recently formed at Christian colleges across the country, including flagship evangelical campuses such as Wheaton College in Illinois and Baylor in Texas.

Obviously this goes back to Judith Rich Harris’ general insight: social consensus and cultural cognition are real phenomena which are enormously impactful. But please remember that this doesn’t necessarily explain non-shared environment, as these sorts of dynamics are forces for conformity and homogenization. When we are thinking about control of outcomes, usually you need to focus on:

– Culture

– Genes

– Parents

In that order. The non-shared environmental variance will still be substantial, but we don’t have a good sense of what’s causing it yet. And we may never. But we can choose a lot of life outcomes by selecting the nation we migrate to, or, by the community with which we identify. For example, if I migrated back to Bangladesh and raised my daughter to be a staunch atheist with a generally liberal-individualist ethos, those values might stick. There’s probably some heritable aspect to my character which makes atheism and liberal-individualism “a good fit.” But, there is a strong chance that my daughter will conform to the milieu in which she grows up, and with which she may identify. The exception to this would be if she found a subculture which insulated her from broader social conformity pressures, and allowed her to develop her worth and identity differently.

I’m not totally sure of the political implications of this perspective in the United States. My own position is that the rhetoric of “family values” on the American Right today has been strongly suffused with an individualist ethos that is common in Anglo-American evanglical Protestantism, and can find its roots in the somewhat atomized nature of Scots-Irish and lowland South culture in the United States. A contrast with this model is that of Mormons, who share values with evangelical Protestants, but whose folkways reflect the more communitarian ethos of New England Yankees and German or Scandinavian peoples. I suspect that the lower divorce rate (and social pathology more generally) among Mormon Americans in comparison to white evangelical Protestants has more to do with the nature of their collective institutions than the individual dispositional nature of believers.

On the other hand, this viewpoint does not necessarily support the instincts of modern technocratic liberalism. In general technocratic liberals seem to think that many social ills have a small number of causes, and so are tractable through public policy. Often these causes are pinned down on single institutions (e.g., schools), or, a lack of funds. Recently universal pre-school has been all the rage because of its near magical ameliorative properties. But the social science on that is decidedly mixed. I suspect that universal pre-school as a simple institutional fix is far inferior to the rich civic and social matrix which Jane Jacobs described in The Death and Life of Great American Cities. Not only because organically developed social and civic institutions provide services which pre-school can not replace, but also because a society which gives rise to such institutions is by its nature more healthy and exhibits less anomie. In some ways Mao was right that a true solution toward fixing social ills is a “cultural revolution.”