Some interesting news comes our way from the developing field of epigenetics, the study of changes in a person’s genetic makeup throughout his or her life that are based on experience and not DNA sequence changes. The Atlantic reported on a recent experiment that suggests that parents pass not only behavioral cues regarding fear and anxiety to their offspring, but modified brain chemistry as well (h/t Elissa Goldstein, who astutely noted, “Science explains Jews”). It’s called “transgenerational epigenetic inheritance,” and it’s pretty interesting stuff.
In the experiment, mice were conditioned to fear acetophenone, a scent commonly used in food flavoring, with a foot shock administered to the mice whenever the smell was present. “The mice’s noses and brains also adapted accordingly, generating additional M71 neurons—cells receptive to this particular scent—so that they would be extra sensitive to the smell,” but that wasn’t all. Here’s what else happened:
However, the crazy part is that the offspring of these mice, who had never before been exposed to that smell, also showed increased fear and startle responses to the scent. This suggests that the learned association, connecting the smell with danger, was passed down from one generation to the next. And this second group’s offspring also showed heightened sensitivity to the odor. Thus, three generations of mice were affected by the conditioning, even though only one of them had actually experienced it. Behind these behavioral effects were similar changes in the noses of each of these offspring groups, with larger M71 receptors present and an increase in the number of M71 neurons available.
All of this is to say that you can finally blame your mother for all your weird anxieties, because science. But first call her, will you?