Don't Mess with Nursing Moms
Sep/20/2011 22:18 Filed in: Aggression
There are few images as sweet as a mother breast-feeding a baby. But new research shows that the reduced arousal from those touching moments may disinhibit a mother's aggression toward others. In short, nursing just might bring out the "mama bear" in any woman -- and rightly so.
It's a well-established fact that mammal mothers are very protective of their offspring. That begs the question of whether the same behavior pattern holds true for women (who are, of course, mammals) and if so, why? The new paper by Jennifer Hahn-Holbrook and colleagues provides an answer. The researchers recruited women who were nursing exclusively, who were bottle-feeding, or who had never been pregnant. They then invited them to play a "game" in the lab where they would compete with other women on reaction time tasks. Who ever "won" a trial (i.e., answered the question first) was able to deliver an aversive sound to the other players under the guise of motivating them to work harder. The other player in each case was a confederate working for the researchers who, by design, was told to act somewhat unfriendly to the real participant during the initial meeting.
So what happened? Just as the researchers predicted, lactating women displayed the most aggression. The aversive sounds they delivered were the longest and the loudest (they could modulate these by pressing buttons) -- they were like the driver on the highway who laid on the horn to let you know just how annoyed she was! What was most interesting, at least to us, was that this heightened aggression wasn't stemming from a need to protect a child. It was just aggression plain and simple.
The researchers also assessed physiological arousal of the women, which revealed that the arousal levels of lactating women were lower (as is common with mammals). Reduced arousal has been associated with decreased regulation of aggressive responses in other work, and in the present case, a women's arousal level was directly predictive of her sound blasts (the lower the arousal the greater the blasts). What this work suggests is that the "sweetness" of nursing can be double-edged. While bonds with a baby grow stronger through nursing, potential aggression against others also rises. This pattern makes great functional sense, as one of a mother's primary concerns is protecting her child from threats. But, it may also explain why a new mom may, for seemingly unknown reasons, feel more like she wants to rip someone's head off if he's annoying her.
So what happened? Just as the researchers predicted, lactating women displayed the most aggression. The aversive sounds they delivered were the longest and the loudest (they could modulate these by pressing buttons) -- they were like the driver on the highway who laid on the horn to let you know just how annoyed she was! What was most interesting, at least to us, was that this heightened aggression wasn't stemming from a need to protect a child. It was just aggression plain and simple.
The researchers also assessed physiological arousal of the women, which revealed that the arousal levels of lactating women were lower (as is common with mammals). Reduced arousal has been associated with decreased regulation of aggressive responses in other work, and in the present case, a women's arousal level was directly predictive of her sound blasts (the lower the arousal the greater the blasts). What this work suggests is that the "sweetness" of nursing can be double-edged. While bonds with a baby grow stronger through nursing, potential aggression against others also rises. This pattern makes great functional sense, as one of a mother's primary concerns is protecting her child from threats. But, it may also explain why a new mom may, for seemingly unknown reasons, feel more like she wants to rip someone's head off if he's annoying her.
