the ends (survival and prolifieration) determine the validity of the trait/behavior.
Wrong. Study some anthropology and get back to us when you have some understanding of the subject on which you are posting.
studying anthropology is meaningless to future selection, it can only tell you what was selected for in past...it doesn't invalidate anything since evironmental condition (which includes all human activity) can change so can the direction of selection...and 20th century being the most violent/deadliest would suggest it may its becoming more selected for?