Natalie Angier in The New York Times:
Not long ago, Julia Fischer of the German Primate Center in Göttingen was amused to witness two of her distinguished male colleagues preening about a topic very different from the standard academic peacock points — papers published, grants secured, competitors made to look foolish. “One of them said proudly, ‘I have three children,’ ” Dr. Fischer recalled. “The other one replied, ‘Well, I have four children.’
“Some men might talk about their Porsches,” she added. “These men were boasting about their number of children.” And while Dr. Fischer is reluctant to draw facile comparisons between humans and other primates, she couldn’t help thinking of her male Barbary macaques, for whom no display carries higher status, or is more likely to impress the other guys, than to strut around the neighborhood with an infant monkey in tow. Reporting in the current issue of the journal Animal Behaviour, Dr. Fischer and her co-workers describe how male Barbary macaques use infants as “costly social tools” for the express purpose of bonding with other males and strengthening their social clout. Want to befriend the local potentate? Bring a baby. Need to reinforce an existing male-male alliance, or repair a frayed one? Don’t forget the baby.