I think Donald Hobson was probably using “50% genetic” to mean “50% heritable”, otherwise I don’t see what “50% genetic” could mean. If I’m being confused here, can you please explain more?
Most estimates for heritability would still be significant even in a genetically identical population (since cultural factors are heritable due to shared family environments). You can try to control for his with twin adoption studies, which controls for shared family environment, but still leaves a lot of different aspects of the environment the same. You could also adjust for all other kinds of things and so get closer to something like the ”real effect of genes”.
I am not fully sure what Donald Hobson meant by “effect of genes” but more generally heritability is an upper bound on the effect of genes on individuals, and we should expect the real effect to be lower (how much lower is a debate with lots of complicated philosophical arguments and people being confused about how causality works).
From Wikipedia:
In other words, heritability is a mathematical estimate that indicates an upper bound on how much of a trait’s variation within that population can be attributed to genes.
Heritability != genetic components!
I think Donald Hobson was probably using “50% genetic” to mean “50% heritable”, otherwise I don’t see what “50% genetic” could mean. If I’m being confused here, can you please explain more?
Most estimates for heritability would still be significant even in a genetically identical population (since cultural factors are heritable due to shared family environments). You can try to control for his with twin adoption studies, which controls for shared family environment, but still leaves a lot of different aspects of the environment the same. You could also adjust for all other kinds of things and so get closer to something like the ”real effect of genes”.
I am not fully sure what Donald Hobson meant by “effect of genes” but more generally heritability is an upper bound on the effect of genes on individuals, and we should expect the real effect to be lower (how much lower is a debate with lots of complicated philosophical arguments and people being confused about how causality works).
From Wikipedia: