Why should we study the genetics of success?

Jer Thorp, flickr.com, CC BY 2.0
Jer Thorp, flickr.com, CC BY 2.0

There are more than a few answers to this question. Probably the most important one is science for science’s sake. We study genetics because the DNA sequence is the beginning, the blueprint for our development and so many of the features that make us the unique individuals we are. Understanding how differences in children’s genes translate into differences in the kinds of people they grow up to be will unlock untold opportunities in the practical realms of medicine and education that may not be immediately apparent to us now.

My own work on the genetics of success is somewhat more applied. I’m interested in finding new ways we can help children grow and develop successfully. We know that genetic differences are one source of variation in children’s outcomes. So, it stands to reason that if we can figure out how those genetic differences work, we can devise environmental interventions that achieve the same effects.

This way of thinking about genetics – as way to learn something about how to design interventions that can work for anyone, regardless of their genotype – has been around for a long time. These days, much attention is focused on so-called “precision medicine.” Precision medicine is the idea that we can tailor treatments to individual patients based on, for example, genetic information. Precision medicine aims to use genetics as part of the treatment process: genetic information about the patient guides individualized therapy. But that’s not the only way to use genetic information to improve human health. An alternative approach is to study genetics to understand the mechanisms that produce disease.

Instead of using genetics in the treatment process, this type of research uses genetics to discover treatment targets: genetic causes of disease in the general population guide development of new therapies that can work for many different patients. That’s the kind of work I’m trying to do. Although in this case, instead of a disease I’m studying a good thing – upward social mobility.

“The treatments I have in mind are policies and programs – interventions that change children’s environments rather than their physiologies.”

In my work, I follow-up discoveries that have been made in giant data mining studies called “genome-wide association studies” or GWAS. GWAS scan the entire genomes of very large samples of people (sometimes hundreds of thousands) to identify variants linked with a trait or outcome. And then they stop. The next step is to follow-up GWAS discoveries to understand how they work.

Most of the time, follow-up of GWAS discoveries is done in a “bottom-up” way. Researchers try to trace a path from the DNA sequence variant discovered in GWAS to some other mechanism of gene regulation or expression, protein production, and so forth. This bottom-up approach aims to uncover the molecular mechanism of genetic action. Often, the ultimate goal is to develop a drug target.

I take a different approach. I work from the “top-down.” I say top-down because I start with the outcome – in this case socioeconomic success – and then I work backward in development to try and understand the processes and behaviors that link that outcome back to DNA sequence. The top-down approach aims to uncover a developmental or behavioral mechanism of genetic action. Like the bottom-up approach, the ultimate goal is a treatment target. But instead of a drug, the treatments I have in mind are policies and programs – interventions that change children’s environments rather than their physiologies.

My work so far, together with collaborators Terrie Moffitt and Avshalom Caspi at Duke and Ben Domingue at Stanford, as well as others, points to a few of these developmental and behavioral mechanisms. In particular, early language development and rapid acquisition of reading skill stand out. These findings suggest the possibility that intervention to promote language development early in life can help get kids on the fast track to success.