This is very interesting stuff.

http://www.bbc.co.uk/nature/14418174

"Researchers studying a colony of Nazca boobies, a colonial seabird, found the birds perpetuate a "cycle of violence".

Juvenile birds that are maltreated by older, non-relatives grow up to become more violent towards other chicks.

It is the first evidence from a wild animal that, as in humans, "child abuse" can be socially transmitted down the generations."