My view is that people should basically talk about heritability less and interventions more. In most practical circumstances, what we’re interested in is how much potential we have to change a trait. For example, you might want to reduce youth obesity. If that’s your goal, I don’t think heritability helps you much. High heritability doesn’t mean that there aren’t any interventions that can change obesity—it just means that the current environments that people are already exposed to don’t create much variance. Similarly, low heritability means the environment produces a lot of variance, but it doesn’t tell you anything specific you can actually do!
If you goal is to find interventions, all heritability gives you is some kind of vague clue as to how promising it might be to look at natural environmental variation to try to find interventions.
On the other hand, there is some non-applied scientific value in heritability. For example, though religiosity is heritable, the specific religion people join appears to be almost totally un-heritable. I think it’s OK to read this in the straightforward way, i.e. as “genes don’t predispose us to be Christian / Muslim / Shinto / whatever”. I don’t have any particular application for that fact, but it’s certainly interesting.
Similarly, schizophrenia has sky-high heritability (like 80%) meaning that current environments don’t have a huge impact on where schizophrenia appears. That’s also interesting even if not immediately useful.
My view is that people should basically talk about heritability less and interventions more. In most practical circumstances, what we’re interested in is how much potential we have to change a trait. For example, you might want to reduce youth obesity. If that’s your goal, I don’t think heritability helps you much. High heritability doesn’t mean that there aren’t any interventions that can change obesity—it just means that the current environments that people are already exposed to don’t create much variance. Similarly, low heritability means the environment produces a lot of variance, but it doesn’t tell you anything specific you can actually do!
If you goal is to find interventions, all heritability gives you is some kind of vague clue as to how promising it might be to look at natural environmental variation to try to find interventions.
On the other hand, there is some non-applied scientific value in heritability. For example, though religiosity is heritable, the specific religion people join appears to be almost totally un-heritable. I think it’s OK to read this in the straightforward way, i.e. as “genes don’t predispose us to be Christian / Muslim / Shinto / whatever”. I don’t have any particular application for that fact, but it’s certainly interesting.
Similarly, schizophrenia has sky-high heritability (like 80%) meaning that current environments don’t have a huge impact on where schizophrenia appears. That’s also interesting even if not immediately useful.