Before someone things this is troll bate, I'm completely aware that epigenetic changes don't change actual DNA sequences. So much for 'unique personalities' and 'free will', and people 'always having a choice'. Oh, and I also forgot economic situations which greatly change how the brain works. Environmental trauma changes the expression of genes.

Two good examples to support this: Caesarian babies don't get their initial bacterial load from the doctors and nurses who handle the baby. Normally babies get their initial bacterial load by exiting through the birth canal. Second is twins separated at birth and thus their diets. By ~25 our gut biome is firmly in place. Their different bacterial profiles would change how the gut produces serotonin, processes glucose/sucrose/fat, and a host of other changes. Things like exposure to parasites and disease (think cats) would also change personality, body shape, and epigenetic expression.