"Still, that any trait in us or other species, psychology or other, is selected by evolution must be true, as any trait selected away by evolution by definition

"Still, that any trait in us or other species, psychology or other, is selected by evolution must be true, as any trait selected away by evolution by definition does not live." This is a false dichotomy. Some traits do not provide enough of an advantage or a drawback to be selected for or against. Some traits reach fixation by piggy-backing on an other advantageous trait (either because they are a byproduct or just because the advantageous trait first appeared in a small insular population that shared that neutral trait.) Some reached fixation because, by chance, they got through an evolutionary bottleneck.