Does Motherhood Change the Brain?

This knack for calmly sailing through the rigors of parenting is no accident, however. Mothers have cooler heads and better coping skills than nonmothers.
It’s all part of the “maternal brain,” according to Craig Kinsley, a psychologist with the University of Richmond. He has presented his findings in the journal Physiology and Behavior this month.
“Reproduction shapes and alters a female’s brain in significant ways,” he said yesterday.
Essentially, the motherly mind does not tend to dwell on fear or confusion in the face of adversity or challenge.

The experiment was done with rats:

He based the conclusions on four years of research with female rats who had, well, their little paws full. Mr. Kinsley and his research team found that veteran mother rats were less stressed by a series of lab challenges than females who had never faced a litter of needy babies.
The rats were placed in an open space as well as inside clear plastic tubing in bright light – hair-raising environments for a rat, according to Mr. Kinsley. The researchers found that the momma rats methodically and fearlessly explored the unknown territories, looking for a way out.
The nonmothers froze up or moved with great caution.
In the aftermath, the mother rat’s brains showed less activation of the amydaglia, an area that regulates fear.
“Pregnancy and offspring create a more adaptive brain, one that’s generally less susceptible to fear and stress,” Mr. Kinsley said.

Nor does the effect seem to vanish:

“But what’s most intriguing is that this seems to be a long-lasting effect which persists throughout life,” he added. “It is not temporary.”

Here is Kinsley’s home page. Here is his claim that pregnancy makes women smarter, in addition to calmer.

My take: I can cite one data point, my mother, in favor of the hypothesis.