Oops, shouldn't have assumed you're talking about genetics :)

Still, if you're talking about character in a causally neutral sense, it seems that you need to posit character traits that hardly change within a person's lifetime. Here I admit that the evidence for rapid institutional effects is weaker than the evidence for institutional effects in general.

(Re: Hong Kong, Singapore, no, I do mean those cities specifically. Their economic outcomes differ strikingly from culturally and genetically similar neighbors because of their unique histories.