People not satisfied with the group they are with can only leave if they take or find some people that they are satisfied with. Cut- you make me shake my head. If men were all rapists, women hiding all the time, getting hurt, men with a completely selfish attitude, not helping with children, it would not make for good reproduction. It is unlikely that we could have the cooperation to simply live, never mind reproduce. We have more efficient ways to curb population than infanticide.
Conventional war evolves to unworkable levels with our capacity to design weapons.
These things are all counterproductive for people. Variety is important, but we can get it easily enough in other ways. AN- that is very strange logic, it doesn't add up. The individual is dead without the group, the group is a vehicle for the individual to live, but to imply it's importance as minor is quite out of touch with reality. You don't always maximise your fitness by reproducing.