The epigenetic lottery

post by Bill Gardner

Tyler Cowen discusses the (possibly diminished) US social mobility, and asks

How much of [social] immobility is due to “inherited talent plus diminishing role for random circumstance”?  Is not this cause of immobility very different — both practically and morally — from such factors as discrimination, bad schools, occupational licensing, etc.?  What are you supposed to get when you combine genetics with meritocracy?  I do not know how much of current American (or other) immobility is due to this factor, but I find it discomforting that complaints about mobility are so infrequently accompanied by an analysis of this topic.

So, the idea is that nature roles the dice and gives each child a set of genetic endowments. Families will also invest their resources in cultivating the children's talents. Then, as we become adults, 'society' (meaning the schools, job markets, etc.) places each of us in the social hierarchies of wealth, income, and power (the figure to the right is from Catherine Mulbrandon [@visualecon], and shows the 2005 income distribution among the bottom 98% -- adding the next 2% takes you way off the page). If societies are increasingly meritocratic, those outcomes will mirror the individual distribution of genetic talent and family resources to an increasing degree. So it could be that reduced mobility and increasing social inequality of outcomes reflects increasingly accurate meritocratic selection processes. And many would argue that such processes are not inherently unjust, so maybe we should just get over being upset about the worsening inequality of outcomes. If you add the ideas that genetic endowments are exogenous, and that trying to compensate for the inequality of family resources is either wrong or futile, then you have even stronger justifications for current inequality.

I don't buy these conclusions, for lots of reasons, but this post is not the place to provide the discussion that Cowen is calling for.

I want to raise just one objection here: The story about the genetic lottery is too simple. Our biology is less exogenous than most theorists believe. Michael Rutter explains that genes do not give us talents:

...although the DNA is what a person inherits, the effects of that DNA are dependent on a chain reaction that ends up with the expression of the products of the DNA in the structure and function of individual cells that is how environments alter genes (emphasis added).

Referring to this account of the interaction of nature and nurture, James Heckman writes

The field of epigenetics surveyed in Rutter (2006) demonstrates how genetic expression is strongly influenced by environmental influences and that environmental effects on gene expression can be inherited (emphasis added).

He then argues that there is evidence

that high quality early childhood interventions foster abilities and that inequality can be attacked at its source.  

and we are therefore not absolved from responsibility for the inequitable distribution of adult talent visible in infancy and early childhood.

The problem I'm pointing to in the meritocratic argument is that there isn't really a genetic lottery  in the way we imagine: and to the degree there is, the dice are loaded in the womb. If Heckman is right, there is much more we can do about inequality than most of us are willing to acknowledge.

However, if Heckman is right, it is also the case that much if not most of what we can do is equalize the epigenetic and child developmental lotteries that will govern inequality among future generations. And we have to decide whether we are motivated to struggle for equality in that future, a promised land that we will not see.

Comments

[Jonathan]

Bill you are also ignoring the fetal origins literature. Even James Heckman might be willing to accept the results from this burgeoning field. Most notably look for research from Janet Currie and Doug Almond for more on this.

[Bill Gardner]

Hi Jonathan,
Thanks for commenting. I am familiar with some of Currie's work and will look into Almond. I'd also appreciate the opportunity to read more of your thoughts about the sense in which I may be ignoring the results of this literature.

I believe that intrauterine effects are very important for development, and have been blogging recently about the importance of universal prenatal care.

[Jonathan]

Hi Bill,
I did not mean this in a negative way. Just that the research is reasonably new to the field. In no way did I intend to mean that you were ignoring the research! Please keep writing, I enjoy the blog immensely. Sorry for the negative connotation, nothing was meant by it!

[Bill Gardner]

No hard feelings, Jonathan. I really did appreciate the comment.