Having a baby boosts oxytocin levels in both men and women. The hormone, which also limits postpartum bleeding, facilitates bonding with an infant, but new research suggests it has some less adorable effects. High levels of oxytocin may also make new parents more aggressive, manipulative, or even violent with each other. Parents may do well to think about oxytocin as similar to a drug in that it provides a high, but comes with potentially harmful side effects. This appears to be particularly true for people in unstable relationships.
“Oxytocin is not the love hormone,” Emory University Neuroscience Professor Dr. Larry Young recently told the American Psychological Association. “It tunes us into social information and allowing us to analyze it at a higher resolution.”
Adam Guastella, clinical psychologist and professor and the University of Sydney, agrees. Guastella’s research on the topic suggests that oxytocin can lead to confrontation precisely because it pushes people to focus on their relationships. When those relationships are happy, there’s no real problem. When relationships are tense, a hormonal surge can trigger additional tension and even outbursts.
“An increase in oxytocin can lead to negative reactions for some people,” Guastella told Fatherly. “For someone who has a lot of anxiety about relationships, or tends to interpret social information in a negative or hostile way, there’s evidence that increased focus can make a person react in a more aggressive way in relationships.”
Research published in the November 2010 journal of Social Cognitive and Affective Neuroscience looked at a sample of people with borderline personality disorder, a mental disorder characterized by emotional dysregulation and conflicted interpersonal relationships, to see if intranasal oxytocin boosts would improve their ability to trust and engage in teamwork. Not so much. Added oxytocin made their maladaptive behaviors worse. Another 2014 study, published in Social and Personality Psychological Science, found that when romantic partners were given oxytocin boosts, it increased abusive behaviors in individuals with aggressive tendencies.
The not-so bad news? It’s extremely rare for oxytocin-driven aggression to be taken out on infants. Animal studies show that even when mice display maternal aggression, upping their oxytocin helps influence nurturing behaviors. However, the added oxytocin can make mothers that much more aggressive towards outsiders. That’s bad news for fathers who have a tenuous or distant relationship with the mothers of their infants. Members of an “outgroup” are unlikely to be treated very well.
“There’s been no investigation on oxytocin’s role in divorce,” he notes. “Oxytocin increases protective instincts so anything seen as a threat would increase aggression.”
The reason the effects of oxytocin are unpredictable (good guys don’t necessarily get better, bad guys don’t necessarily get worse) is that different people have anxieties about different kinds of relationships. “Saying, ‘This is who oxytocin works for and who it doesn’t work for,’ would required hundreds of studies of hundreds of people,” Guastella explains. Those studies haven’t happened yet so Guastella and other researchers are loath to make recommendations for parents.
What Guastella will say, and what is certainly true, is that the hormonal shift that occurs in new parents can have a dramatic effect on personal relationships and therefore it behooves partners to have honest conversations before a child arrives.