Mothers are less stressed out when you put them in a stress-inducing situation. They don’t show as much fear. They are more efficient at foraging. They will find food, collect it quickly and get back. They are more aggressive at defending their offspring; if there is an intruder or any sort of threatening presence, moms will fight it more than non-mothers. A recent study showed that moms are better at recognizing emotions than others. Mothers are able to recognize hostility, disgust, fear or the types of emotions that would trigger some sort of danger to their offspring.
Is it fair to say that the more kids a woman has, the smarter she becomes?
I am not going to say that it is not true, but we haven’t shown conclusively. Studies with mothers that have had multiple birthing events suggest in some cases that they are better at some of these things. Essentially, the moms become more efficient at being moms the second time around. But, I don’t have conclusive, concrete, “Yes, have 15 children, you’ll be successful.”
“The bodily changes of childbearing are obvious, but as we are discovering, the changes in the brain are no less dramatic,” you and your research partner, Craig Kinsley, wrote in Scientific American in 2010. How so?
You can actually look and find neurons that are bigger in mothers than in non-mothers. You can do a stain just to look for the number of branches that come off of a neuron to make connections with new neurons. There are large differences in the number of neurons that are firing. We can see that there are more receptors for certain hormones that are present. Then, we can also see things indicating that different areas of brains are being affected. A mother brain might be using more brain regions to figure out a memory task.
It is sort of like the physical changes in pregnancy. In the cases of rats and people too, you can see, oh, look, you are six months or eight months or nine months pregnant. That’s a very obvious physical change. I think a lot of those similar things are happening in the brain, you just don’t see anything taking place there.
You can sort of see these things happen in human females. I know that when my wife was pregnant one of the things that she was very sensitive to was fried chicken. It was one of those things where she would put a fist to her mouth and run in the opposite direction. It just made her sick to her stomach. I think what is happening there is a rewiring of the brain. Smells that were appetizing beforehand are now repulsive. That may not be a long-term thing. Now, my wife likes chicken again.
Again, I hope my wife doesn’t mind too much here. She was very emotional and would cry at not only Hallmark commercials but also other seemingly innocent commercials, which would have me very confused as to what was going on emotionally. But again, I think that’s the brain rewiring. It is rewiring from, okay, I have a standard reaction to other individuals, or a standard amount of empathy, and that empathy is now increasing so that I can better protect my offspring when it gets here.
What are your major unanswered questions?
Previous research has shown some of the stuff I’ve talked about—that there are neurons getting bigger and more efficient. But, in some of the memory scenarios or aggression or foraging, we are not necessarily sure. Is it more neurons? Is it longer bursts of period for neurons that are activated to help make moms more efficient or better at these tasks?