New neuroscience research suggests that gender stereotypes are deeply rooted in the brain.

“Our study was aimed at investigating the neural bases of social cognition, which regulates our behavior and is heavily affected by prejudices and stereotypes,” said study author Alice Mado Proverbio of the University of Milano-Bicocca.

“We discovered specific brain areas were involved in storing and processing this information, i.e.: the middle frontal cortex and the temporo/parietal junction, known to also support the ability to attribute intentions and meanings to the behavior of others,” she explained.

In the study, the researchers monitored the brain activity of 7 female and 8 male Italian university students with an EEG while they each read different sentences off a computer screen. To prevent the participants from figuring out what the research was about, they were told to hit a button whenever they read a sentence that ended with an animal word. They read 240 sentences that did or did not violate gender stereotypes and 32 other sentences ending with an animal word.

The researchers found that sentences that violated gender stereotypes elicited particular patterns of brain activity, known as event-related potentials (ERPs), which are typically observed after reading or hearing grammatical errors.

“Even well-educated persons such as university students with sophisticated or left-wing ideals share the same gender bias prejudice as everybody else, based on what the media or the current knowledge drives,” Proverbio told PsyPost.

“Indeed, our brain automatically detects statistical frequencies or regularities of events, based on our experience, and if it happens to encounter more often a male computer scientist and a female beautician than the reverse, this information is stored as such and used to make predictions and understand the world.”

The study was recently published in the peer-reviewed journal Neuroscience.

“We found that, regardless of what is politically correct or not, people’s brains revealed to be deeply sexist in that it responded with violation signals to sentences where women performed typically male jobs and vice versa (e.g., ‘Here is the commissioner with her husband’ or ‘Hanged the clothes out to dry and caught up with his wife’),” Proverbio said.

“The fact that the prejudice violation elicited enhanced grammar-related electrophysiological components (such as the N400, P600 and the LAN) might suggest that gender prejudices are so deeply rooted in our mind that their violation is treated like a morphosyntactic or linguistic error.”

“In this specific study, we were unable to collect implicit measures of subjective gender stereotypes,” Proverbio noted. “In a follow-up study, we included ERP recordings and the administration of the Implicit Association Test (IAT) on a statistically similar cohort, and did not find any sign of an implicit bias at behavioral level, but again found strong electrophysiological evidence of gender-biased prejudice. This dissociation suggests how sensitive brain potentials are in telling us how we really see the world, notwithstanding what our ideals are.”

The study, “Electrophysiological markers of prejudice related to sexual gender“, was also co-authored by Andrea Orlandi and Evelina Bianchi.