They are pretty horrible to each other at times too. More or less illustrates the somewhat Hobbesian idea of continual reduction of violence since probably the last common ancestor to today.
What I find fascinating is the bifurcation of R-rated behaviors between chimps (violence) and bonobos (sex). I read somewhere about a similar bifurcation in species of dolphins or porpoises where there were was one species which would exhibit high levels of violence and another which was all about the sexy fun time, but that was 30 years ago or so I read it and I have little hope of ever recovering that information (assuming it’s even true, which is not guaranteed for popular science reporting).
This is a myth. Bonobos are at times more than happy to bash each other's heads in, and chimps shag a lot.