Harden is a professor of clinical psychology at University of Texas, Austin. She studies the influence of genetics on life outcomes. The book describes the methodology and tools used in her research and the related findings. The goal of the book is to argue that these findings can be used to improve the life outcomes of everyone, no matter what genetics they inherited in the genetic lottery.
This research, unfortunately, touches on the old-time arguments by eugenicists and racists. To avoid providing ammunition to those arguments, others argue to completely ignore any discussion of genetics on social policy aimed at improving life outcomes.
The book strongly argues against both those approaches. It provides a framework for using the findings to improve the effectiveness of social policies to improve people’s lives.
Some take-aways:
Typical genetic testing by companies like “23 and me” detects a subset of genetic markers (SNP’s). With a large enough number of people (millions), researchers can identify SNP’s that are correlated with the outcome of interest. Correlations are small, in the 0.1% range, but can be combined to develop a polygenic index. The polygenic index may have a correlation up to 10-20% on the outcome of interest.
Most existing studies focus on people of European (white) background. The polygenic indices really cannot be applied to populations from other racial backgrounds. The indices likely do not capture all the SNP’s that affect outcomes.
The SNP’s measured in the current genetic testing techniques only detect a very small subset of a person’s genetics. If an SNP is correlated to an outcome, the actual gene involved is not known. Genes near the SNP are inherited in large chunks. Mixing of genes from the parents is via huge stretches of each chromosome — maybe only 30-40 chunks of the whole genome are mixed.
Opinion on the book:
Some interesting information on the science and findings. I found there was too much emphasis on countering the “eugenics” argument. My prior already rejects eugenics. The counter-argument versus completely ignoring genetics in social policy is new to me, but again, my prior would reject that also.