227: Genes for disease vs. personality, Parental influence, Environmental genes

In today's show, Dr. Lisle discusses: 1. I know you propose that personality is 100% genetically driven. But Dr. McDougall has shown that genes can be turned on and off by diet, and that even the DNA of twins may diverge over time if each twin is raised separately on different diets. Might the same thing be true of the genes behind our personalities? That certain genes could be switched on or off by environmental impacts. And if so, wouldn't that mean that nurture (along with nature) does in fact affect personality? 2. Though parents don't shape their children's personalities, that time at home can leave all sorts of lasting outcomes including anything along the spectrum of wonderful to terrible memories, respectful relationships or bitterness and resentment toward one another, great financial inheritance or debt, and generally, the set of examples and information made available or limited for the child can heavily influence their life choices and performance. After can't a child and emerging adult only work with the ideas they have available to them, and can't they get set into certain ruts of ideologies and perspectives including their religious beliefs? 3. I am sold on your lucid explanations of how behavioral genetics shapes personality.    So doesn't if naturally follow that by going back in time to study differences between the ecological/ political /religious influences in different areas of the world throughout our history,  that we can use these differences to speculate as to how these differences have shaped personality in different areas of the world.  The question is, can you identify or speculate on historical factors that may explain statistical differences in personality between different peoples.