Len, Sriram,
This approach, just attributing all behaviour to genetics/epigentics is too broad brush to be of any use at all, it is just a reduction to banality.
Unless, for each behaviour, you can tell me which genes, switches, proteins and hormones are involved, there is no point in taking you seriously.
I had biueberries at breakfast this morning. This is because of genetics/epigenetics? Not because they were in abundance in the market yesterday?