This is also just not really true. Natural Selection (as opposed to genetic drift) can maintain genetic variations especially for things like personality, due to the fact that “optimal” behavioural strategies depend on what others are doing. Any monoculture of behavioural strategies is typically vulnerable to invasion by a different strategy. The equilibrium position is therefore mixed. It’s more common for this to occur due to genetic variation than due to each individual using a mixed strategy.
Furthermore, humans have undergone rapid environmental change in recent history, which will have selected for lots of different behavioural traits at different times. So we’re not even at equilibrium.
I think a better argument than #2 would be that evolution tends to remove genetic variantions.
This is also just not really true. Natural Selection (as opposed to genetic drift) can maintain genetic variations especially for things like personality, due to the fact that “optimal” behavioural strategies depend on what others are doing. Any monoculture of behavioural strategies is typically vulnerable to invasion by a different strategy. The equilibrium position is therefore mixed. It’s more common for this to occur due to genetic variation than due to each individual using a mixed strategy.
Furthermore, humans have undergone rapid environmental change in recent history, which will have selected for lots of different behavioural traits at different times. So we’re not even at equilibrium.