Researchers studying Rhesus Macaque mothers and writing on their results in Current Biology have determined that interactions of macaque mothers with their infants have a lot of similarity to human mothers in the first month of a newborn's life.
"What does a mother or father do when looking at their own baby?" asks 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, newborns are in tune with their mother's expressions, movements and voice, and mutually engage their mothers. What about infant monkeys?
"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.
The 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.
Why after only a month?
"It's quite puzzling," Ferrari said, "but we should consider that macaque development is much faster that of humans. Motor competences of a two-week-old macaque could be compared to an eight- to twelve-month-old human infant. Thus, independence from the mother occurs very early… what happens next in the first and second month of life is that infants become more interested in interacting with their same-age peers."
The findings offer new insight into the origins of such mother-infant behavior. "Our results demonstrate that humans are not unique in showing emotional communication between mother and infant," the researchers wrote. "Instead, we can trace the evolutionary foundation of those behaviors, which are considered crucial for the establishment of social exchange with others, to macaques. Mutual gaze, neonatal imitation, infant gestures, and exaggerated facial gesturing by mothers are distinctive signs in macaques, as well as in humans, of interpersonal communication and perhaps even a mutual appreciation of others' intentions and emotions."
The researchers include Pier Francesco Ferrari, Universita di Parma, Parma, Italy, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD; Annika Paukner, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD; Consuel Ionica, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD; and Stephen J. Suomi, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD.
- PHYSICAL SCIENCES
- EARTH SCIENCES
- LIFE SCIENCES
- SOCIAL SCIENCES
Subscribe to the newsletter
Stay in touch with the scientific world!
Know Science And Want To Write?
- The Plot Of The Week: CMS Search For Majorana Neutrinos
- Think Mosquitoes Bite You More Than Other People? Here's Why You May Be Right
- We're Playing Classical Music All Wrong
- Football Physics: The Science Of Deflategate
- Reviews In Physics - A New Journal
- Happy 150th Birthday To Maxwell's Theory Of Electromagnetism
- Promonitor Index: 5 Key Ways To Assess Reef Health
- "Catholics were first. Perhaps you mean Holy Roman Catholic, but the first Christian prayer says..."
- "I concur - in fact I have been battling in CMS for error bars be always plotted. However, note..."
- "Hi,will fix the typo.About the bars: please bear in mind that the error bars in the graphs are..."
- "So, a scandal from the Catholic version of Football (we in Britain follow the true and original..."
- "Your article makes no sense! What if the pats heat their footballs up to 120 degrees before the..."
- Study identifies geographic long-term clusters of anti-vaccine beliefs in Northern California
- Sociologists discover young women and men prefer egalitarian relationships
- Citizen scientists have positive news for Puget Sound seabirds
- Sleeping on stomach increases risk of sudden death in epilepsy
- BPA exposure during pregnancy correlated to oxidative stress in child, mother