Hexadecanal (HEX), a chemical released by a newborn baby influences aggression in adults who are exposed to it. The molecule triggers aggression in women as it decreases connectivity in parts of the brain linked to social decision-making, but it increases this connectivity in men. The study claims that it is tied down with evolutionary purposes to increase the infant’s chances of survival.
HEX Chemical in Newborn Infants Influences Aggression in Adults
HEX is a chemical that is recently discovered that reduces stress responses in mice through social buffering, according to a 2015 study. But a more recent study found that it could also reduce the startle response of a human, which suggests that it can modulate human behavior.
According to New Atlas, the new study investigates how HEX could influence sex-specific aggression in humans. They recruited 200 participants and tested them on two different behavioral experiments. They found that HEX can indeed affect a person’s aggressive responses.
Despite having no perceptible odor, sniffing HEX specifically affects aggressive responses differently in men and women. Men displayed decreased aggression, while women displayed increased aggression. Functional magnetic resonance imaging (fMRI) shows that HEX increased activity in the left angular gyrus in both sexes, but the connectivity from that brain region differed between sexes.
Researchers explained that there is more social regulation in men that kept their aggression in check, while there is decreased regulation in women that can be triggers aggression and can be viewed as a signal to be set free.
Effects of HEX May Have Evolutionary Origins
As reported by Medical Xpress, researchers believe that the difference in how HEX affects both sexes may be explained by evolution. Male aggression usually translates to aggression towards newborns that may lead to infanticide, a real and common phenomenon in the animal kingdom.
Moreover, female aggression is usually seen in mothers defending their young from predators or keeping them safe from harm. Like males, this behavior is also common in the animal kingdom.
Japanese researchers verified this claim and found that HEX is one of the most abundant chemicals, if not the most abundant, in a newborn baby’s brain.