Vasopressin sprayed up the nose resulted in men showing more attention to babies.
Vasopressin is a hormone that is active in the father’s brain. The hormone influences behavior by binding to its 1a receptor in the brain. The vasopressin 1a receptor differs between and within species. How does the vasopressin hormone and its 1a receptor shape men’s family life? So far, it’s a bit of a mystery.
A study of Swedish men found associations between types of vasopressin 1a receptor and men’s (but not their wives’) reported scores on a partner bonding questionnaire and their likelihood of divorce.
We know that vasopressin is active in other species. Prairie voles form long-term pair bonds and share parental roles. The type of vasopressin 1a receptor helps account for male prairie voles’ parental behaviors. Genetic experiments that change an individual’s vasopressin receptor type can also impact that male’s family behaviors.
Related effects can be induced in human males. When researchers immersed Dutch men in a virtual world of baby avatars and sprayed vasopressin up their noses, the men started paying more attention to the babies. Vasopressin sprayed up the nose also resulted in men showing more empathy and concern when watching distressing or uplifting videos – but only men who were already rated as warm fathers to their children.
But beyond that we know very little. How might changes in men’s vasopressin receptors or use of an intransasal spray influence their family lives? The science of fatherhood will surely have more to say about such questions in the future!