I seen a program on Discovery about primates there is one group of "Monkeys" that do it for just about each and every reason that comes along.Terry L. Mair Mair's Photography
Bonobos they are.I have translated a book of BBC serial by John Sparks "Battle of Sexes in the Animal World" from English into Estonian, and bonobos are very "human", even hyperhuman. They do it when happy and when sad, when aggressive and when submissive and anytime.
Why speak - lets do it!Peeter