Tamarin and marmoset monkeys: an inspiration for human fathers

Cotton-top tamarin father carrying an infant. (Photo credit Carla Y. Boe)

The way tamarin and marmoset monkey fathers parent is strikingly similar to how hands-on human fathers parent when the family is working well together.

Tamarin and marmoset monkeys (small monkeys from South America) share something very particular with human beings – all are “cooperative breeders”. Cooperative breeding means that the young thrive better when the whole family works together to care for infants. The way tamarin and marmoset monkey fathers parent in this cooperative arrangement is strikingly similar to how hands-on human fathers parent when the family is working well together. These monkeys have something to teach us about the art of co-parenting.

Fathers can be remarkably competent in raising children. My research shows that tamarin and marmoset fathers (and other male family members) are very involved in child care. Males lose weight (up to 10%) as they carry youngsters on their backs for most of the day. Fathers’ weight loss is reduced if there are other males to assist him in childcare. Mothers only carry infants for brief periods of time during nursing. Males also share food with their young at the time of weaning, making the end of nursing easier for mothers. This food sharing helps young quickly become expert foragers, able to feed themselves.

How do these monkey fathers become so competent and involved? First, a key to father’s involvement with infants is a strong relationship with the mother. Across all mammal species pair bonding and monogamy always come first before fathers are involved in infant care. The pair bond assures each parent of the involvement of the other when infants arrive.

Second, male monkeys appear naturally attracted to infants and are motivated to help. But paternal care skills must be nurtured. Young males assist their fathers with child care and in the process learn important parenting skills. Monkeys that do not have experience caring for someone else’s infants as they grow up have poor success when they become parents. Thus, they must learn parenting skills. Furthermore, mothers must allow males to take care of their infants. Infants whose mothers are overly possessive do not thrive.

Males also experience hormonal changes during their mate’s pregnancy. As pregnancy progresses, males show increased levels of typically female hormones such as estrogen, prolactin and oxytocin which may prepare the male to take care of infants. Males also gain weight during their mate’s pregnancy perhaps to compensate for the weight loss they will experience during child care. Similar findings have been seen in human males who are emotionally involved in their partner’s pregnancy.

These monkeys illustrate several important points about fatherhood in the context of cooperative breeding which are applicable also to humans:

  • Fathers can provide good quality infant care, but infant care is costly (as illustrated by weight loss in monkeys).
  • A good relationship between parents is needed for good parenting success.
  • Males are interested in being with infants but they must also learn parenting skills.
  • Mothers must permit fathers (and others) to help them with infant care.
  • Fatherhood and infant care change a male’s hormones with increasing levels of hormones typically associated with mothers and infant care.