alt Hacker NewsFTA: “We use mathematical modeling and analyses of twin cohorts raised together and apart”
So, take one cohort of twins raised together and see how well their life spans correlate.
Take another cohort of twins separated at or near birth and do the same.
Then, do some math magic with both to estimate heritability.
Replies
tptacek • yesterday at 4:51 PM
The obvious problem you run into with twins raised apart is that there in fact aren't many twins who are raised apart.
➕ show 1 reply
moi2388 • yesterday at 4:56 PM
Yes but those aren’t random samples. Children not raised with their birth parents had different circumstances. As did children who got split up, and families adopting children is also a selection bias.
This is incorrect. Twin studies typically compare MZ twin similarity against (same sex, usually) DZ twin similarity. Assuming that there is nothing special about MZs for the trait (e.g. in this case if MZ twins lived longer by virtue of being MZ twins), you can estimate heritability free of shared environments.