•Genetic similarity is some 99.5%, potentially 100%, from the same 2 starter cells, following the same cellular propagation ("phi"), unto the same sorts of chemical signals, compounds, and (importantly) rewards.
•Social interest and investment, personality, attractiveness, skillfulness, anatomy, energy levels, and other aspects of genetic expression are basing on nutriments, a most simple, logical method of cellular energy / youth.
•Life is simple and easy (with knowledge).