An article in the journal Genetics that came out this week, “Estimates of the Heritability of Human Longevity Are Substantially Inflated due to Assortative Mating” used 54 million family trees and more than one billion ancestors and relatives from Ancestry.com to understand the question: Is a longer life heritable and based on genetics?
The answer that researchers from Google’s(Alphabet’s) Calico and Ancestry.com came to is that longevity in humans is probably not very dependent on genetics and that heritability of longevity is under 10 percent. As a comparison, the genetic heritability of eye color has been estimated to be between 60-100 percemt.
Though the answer might seem a little shocking, it really isn’t that new. Most studies have estimated that the heritability of human longevity is usually only around 20-30 percent or less. The authors of this new study say that previous estimates were much higher because previous researchers failed to take assortative mating into account. Put another way, they ignored the fact that individuals with similar genotypes and phenotypes tend to mate.
There are two other things I found interesting in this article
First, the authors found that lifespans of spouses were correlated as much or more than relatives.
Second, the authors argue that sociocultural status is heritable and has relevance to human longevity.
This reinforces the need to discuss how things like education and socioeconomic status are heritable, as well as being major indicators of health and lifespan. Obviously, children of parents who graduate college are more likely to go to college and children of wealthy parents will inherit the parents’ wealth and connections, including being able to afford insurance and other health-related interventions.
We are generally stuck with the genetics we are born with. Gene therapy and genetic engineering can change that, but it has only started to take effect. If sociocultural factors are heritable, is there something like gene therapy that can be applied on the sociocultural level to give the benefits of the positive factors without being born into them?
Could we engineer a cultural virus?