Inhaled oxytocin increases positive social behaviors in newborn macaques.
Early caregiver-infant interactions are critical for infants' socioemotional and cognitive development. Several hormones and neuromodulators, including oxytocin, affect these interactions. Exogenous oxytocin promotes social behaviors in several species, including human and nonhuman primates. Although exogenous oxytocin increases social function in adults--including expression recognition and affiliation--it is unknown whether oxytocin can increase social interactions in infants. We hypothesized that nebulized oxytocin would increase affiliative social behaviors and such effects would be modulated by infants' social skills, measured earlier in development. We also hypothesized that oxytocin's effects on social behaviors may be due to its anxiolytic effects. We tested these hypotheses in a blind study by nebulizing 7- to 14-d-old macaques (n = 28) with oxytocin or saline. Following oxytocin administration, infants' facial gesturing at a human caregiver increased, and infants' salivary oxytocin was positively correlated with the time spent in close proximity to a caregiver. Infants' imitative skill (measured earlier in development: 1-7 d of age) predicted oxytocin-associated increases in affiliative behaviors--lip smacking, visual attention to a caregiver, and time in close proximity to a caregiver--suggesting that infants with higher propensities for positive social interactions are more sensitive to exogenous oxytocin. Oxytocin also decreased salivary cortisol, but not stress-related behaviors (e.g., scratching), suggesting the possibility of some anxiolytic effects. To our knowledge, this study provides the first evidence that oxytocin increases positive social behaviors in newborns. This information is of critical importance for potential interventions aimed at ameliorating inadequate social behaviors in infants with higher likelihood of developing neurodevelopmental disorder.
Laboratory of Comparative Ethology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Poolesville, MD 20837;Dipartimento di Neuroscienze, Università di Parma, 43100 Parma, Italy; and simpsonea@mail.nih.gov.
Elizabeth A
EA
Simpson
Dipartimento di Neuroscienze, Università di Parma, 43100 Parma, Italy; and.
Valentina
V
Sclafani
Laboratory of Comparative Ethology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Poolesville, MD 20837;
Annika
A
Paukner
Department of Psychology, University of Massachusetts, Amherst, MA 01003.
Amanda F
AF
Hamel
Department of Psychology, University of Massachusetts, Amherst, MA 01003.
Melinda A
MA
Novak
Department of Psychology, University of Massachusetts, Amherst, MA 01003.
Jerrold S
JS
Meyer
Laboratory of Comparative Ethology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Poolesville, MD 20837;
Stephen J
SJ
Suomi
Dipartimento di Neuroscienze, Università di Parma, 43100 Parma, Italy; and.
Pier Francesco
PF
Ferrari
D000280:Administration, Inhalation; D000819:Animal Communication; D000818:Animals; D000831:Animals, Newborn; D001522:Behavior, Animal / Q000187:drug effects* / Q000502:physiology; D005260:Female; D006854:Hydrocortisone / Q000378:metabolism; D007100:Imitative Behavior / Q000187:drug effects / Q000502:physiology; D008253:Macaca mulatta / Q000502:physiology / Q000523:psychology*; D008297:Male; D023421:Models, Animal; D010120:Oxytocics / Q000378:metabolism / Q000494:pharmacology; D010121:Oxytocin / Q000378:metabolism* / Q000494:pharmacology*; D021641:Recognition, Psychology / Q000187:drug effects / Q000502:physiology; D012463:Saliva / Q000378:metabolism; D012919:Social Behavior
D010120:Oxytocics; D010121:Oxytocin; D006854:Hydrocortisone
imitation recognition; individual differences; neonatal imitation