Monkey moms go gooey over newborns

Monkey mothers interact with their newborn babies in much the same way human moms do, suggests a study of rhesus macaques.

Last Updated: Oct 09, 2009, 23:30 PM IST

Washington: Monkey mothers interact with their newborn babies in much the same way human moms do, suggests a study of rhesus macaques.
Published in Current Biology, a Cell Press publication, the new findings show that mother macaques and their infants have interactions in the first month of life that the researchers say look a lot like what humans tend to do.

"What does a mother or father do when looking at their own baby?" asked Pier Francesco Ferrari of the Università di Parma in Italy. "They smile at them and exaggerate their gestures, modify their voice pitch—the so-called "motherese"—and kiss them. What we found in mother macaques is very similar: they exaggerate their gestures, "kiss" their baby, and have sustained mutual gaze."

In humans, those communicative interactions go both ways, research in the last three decades has shown. Newborns are sensitive to their mother``s expressions, movements, and voice, and they also mutually engage their mothers and are capable of emotional exchange.

"For years, these capacities were considered to be basically unique to humans," the researchers said, "although perhaps shared to some extent with chimpanzees."

The new findings extend those social skills to macaques, suggesting that the infant monkeys may "have a rich internal world" that we are only now beginning to see.

To reach the conclusion, researchers closely observed 14 mother-infant pairs for the first two months of the infants`` lives. They found that mother macaques and their babies spent more time gazing at each other than at other monkeys. Mothers also more often smacked their lips at their infants, a gesture that the infants often imitated back to their mothers.

The researchers also saw mothers holding their infant and actively searching for the infant``s gaze, sometimes holding the infant``s head and gently pulling it towards her face.

In other instances, when infants were physically separated from their mothers, the parent moved her face very close to that of the infant, sometimes lowering her head and bouncing it in front of the youngster. Interestingly, those exchanges virtually disappeared when infants turned about one month old.

The researchers concluded: “Our results demonstrate that humans are not unique in showing emotional communication between mother and infant.

“Instead, we can trace the evolutionary foundation of those behaviours, which are considered crucial for the establishment of social exchange with others, to macaques.”