There is also little consensus among researchers about what causes psychopathy. Considerable evidence, including several large-scale studies of twins, points toward a genetic component. Yet psychopaths are more likely to come from neglectful families than from loving, nurturing ones.
I’m confused here. If there’s a big genetic component, wouldn’t it stand to reason that parents of psychopaths are more likely to be neglectful and less likely to be loving and nurturing? So why the “Yet” in the quote above? Or is there something I’m missing?
P.S. in response to commenters: Yes, I agree that it’s possible for psychopathy to be largely genetic without parents of psychopaths being much more likely to be neglectful.
What I didn’t understand was Seabrook’s implication that this would be surprising, the idea that if (a) a trait is genetically linked, and (b) a trait can be (somewhat) predicted by parental behavior, that the combination of (a) and (b) should be considered puzzling. By default, I’d think (a) and (b) would go together.
Maybe adoption studies would reveal this? Although there's also the gene-environment interactions. Adopting a psychopath might be bad for the general level of loving and nurturing within a family?
Perhaps he is referring to a study where children grew up in homes that were not their biological parents but still provided a loving environment.
The studies typically compare fraternal and identical twins growing up in the same house, you can see how that would work.
Amending my previous comment from memory – I meant "in the same families" as compared to adoption studies, not "in the same families" as in families with both fraternal and identical twins.
Just because you carry the genes doesn't mean you express them. These kinds of things tend to be multi-allele traits, you need some magic combination of alleles in order to express the actual trait of psychopathy. Just because your folks passed on the necessary genes, doesn't mean that they had the right combination of factors in place to express them. And if you look at a family tree that contains psychopathy, the trait will only be expressed sporadically.
To above commenters: Yes, I agree that it's _possible_ for psychopathy to be largely genetic without parents of psychopaths being much more likely to be neglectful.
What I didn't understand was Seabrook's implication that this would be _surprising_, the idea that if (a) a trait is genetically linked, and (b) a trait can be (somewhat) predicted by parental behavior, that the combination of (a) and (b) should be considered puzzling. By default, I'd think (a) and (b) would go together.