Study: Breastfeeding Mothers have a Protective Instinct like Mama Bears

A small study conducted by researchers in UCLA Department of Psychology suggests that mothers who breastfeed their babies have a mother bear like protective instinct towards their infant than mothers who bottle feed. The study also adds that these women have a lower blood pressure than other women.

Published in the September issue of the Psychological Science, a journal of the Association for Psychological Science the research says that breast feeding mothers have an aggressive instinct of protecting themselves and their babies. The research results say that due to breastfeeding the body’s usual response to fear is dampened giving women an extra edge and courage to defend themselves and their babies. This is similar to how mama bears are seen to protect their young ones and therefore it is being called the ‘mama bear’ affect.

According to Jennifer Hahn-Holbrook, a postdoctoral fellow in the UCLA Department of Psychology and the study’s lead author,”Breast-feeding has many benefits for a baby’s health and immunity, but it seems to also have a little-known benefit for the mother. It may be providing mothers with a buffer against the many stressors new moms face while at the same time, giving mothers an extra burst of courage if they need to defend themselves or their child.”

Jennifer adds though that the aggression does not mean that mothers will go out and ask for trouble. They only have a more aggressive attitude towards protecting their newborn and themselves.

“Breast-feeding mothers aren’t going to go out and get into bar fights, but if someone is threatening them or their infant, our research suggests they may be more likely to defend themselves in an aggressive manner,” she said.

The reaction of breastfeeding mothers is known as “lactation aggression” or “maternal defense” in mammals. The researcher says that although it is known that non-human mammals such as macaques, rats, mice, hamsters, lions, deer, sheep and others, display more aggression when they are lactating than at any other reproductive stage with humans this reaction was not previously studied.

To bring her theory to light, the researcher selected a small group of women. Of them 18  were nursing mothers, 17 were women who were feeding formula their babies and 20 were non-mothers.

Each woman was asked to compete in a series of computerized time-reaction tasks against a research assistant posing as an overtly rude study participant. The women’s infants were supervised in an adjoining room. When the women won a round they were asked to press a button and give a ‘sound blast’ to the loser as an act of aggressiveness.

The study showed that breastfeeding mothers delivered a sound blast that was more than twice as loud and long as non-mothers and double the aggressiveness displayed by bottle feeding mothers. This was true both before and after they nursed their infants.

Also, breast-feeding mothers’ systolic blood pressure was found to be approximately 10 points lower than women who were feeding formula and 12 points lower than non-mothers.

Because similar research on non-human mammals have shown that lactation enables heightened defensive aggression by down-regulating the body’s response to fear the researchers believe the same applies to humans too which is proved by the lower blood pressure.

Related Articles:



About the author


Atula is a writer, traveler and a nature-lover. She is also mom to a boy who seems to have inherited all her creative genes. When Atula is not busy making up stories with her son, she writes for numerous magazines, websites and blogs. She is also working on her site on endangered species called

Leave a Comment