"Cubit" wrote:

When you consider that sperm from different males actively compete, when in
the same test-tube, we might deduce that our ancestors were very naughty.

Various studies show roughly 5% of children are raised by fathers
who don't know they aren't the biological father (varies by study
and by economic status within study so the 5% is only a rough
average). It seems our current population is as well.

Hunter gatherer societies don't have locking doors or any other
method for keeping women from having sex outside of marriage,
and it's clear from that 5% thing that that phase of hundreds of
thousands of years still dominates our evolution.