"In a recent study of wild A. geoffroyi, there was a dramatic change in the rate at which females received embraces when they had young infants than at other times, and females without infants appeared to give embraces in order to gain access to infants (Slater et al, 2007)." Spider Monkeys; Behavior, Ecology and Evolution of the Genus Ateles, ed Christina J. Campbell, 2008.
The findings don't surprise me. But it does make me wonder why humans go to such great lengths to remove body hair. Don't we want to be warm and fuzzy? I think it's a great look myself :-] (Victor Rodriguez graphics.)