Neuroimaging study reveals hate speech dulls brain’s empathy responses

An experimental neuroimaging study in Poland found that exposure to hate speech diminishes the brain’s response to stories about other people suffering. The effect was present irrespective of the group membership of the person suffering in the story – whether they were Polish, like the participants, or Arab. The study was published in Scientific Reports.

Hate speech is a form of communication that involves the expression of discriminatory, hostile, or prejudiced sentiments and ideas directed towards individuals or groups based on their race, ethnicity, religion, gender, sexual orientation, disability, or other characteristics. It is typically conducted by using offensive language, slurs, stereotypes, or threats that aim to demean, degrade, or incite harm or violence against targeted individuals or communities.

Hate speech is considered harmful because it fuels discrimination, hostility, and even acts of violence. It can lead to social division and undermining the principles of equality and respect for diversity. Many countries have laws and regulations in place that prohibit hate speech in order to protect vulnerable populations and promote tolerance.

On the individual level, people exposed to hate speech in their environment become accustomed to it. This makes them more likely to use derogatory language themselves and to engage in other forms of discrimination against other groups. In a similar way to how exposure to violence makes people less emotionally responsive and empathetic when observing violence, it is possible that exposure to hate speech might also reduce empathy.

Study author Agnieszka Pluta and her colleagues wanted to explore whether this is indeed the case. They hypothesized that exposure to hate speech will decrease activity in regions of the brain that are considered essential for processing information about experiences of other people, namely the anterior cingulate cortex and the anterior insula.

They also anticipated a decline in the activity of the theory of mind network – a network of interconnected brain regions vital for comprehending others’ feelings and experiences, or mentalizing. This would especially be true when participants observed the suffering of those outside their group. This network encompasses the temporoparietal junction, precuneus, posterior superior temporal sulcus, medial prefrontal cortex, and temporal poles. The researchers further expected that hate speech exposure would diminish activity in areas that resonate with pain when observing another’s suffering, irrespective of that person’s group identity.

The study included 32 Polish adults, averaging 24 years in age. Out of these, 18 were female, and none reported any neurological or psychiatric conditions. For the experiment, participants were equally split into two groups.

One group of participants viewed hateful comments against Arabs and Muslim immigrants and refugees in Europe (e.g. “It is high time. This wall should have been put up a long time ago. We need to defend Europe against the hordes”). The other group viewed relatively neutral comments about current social issues (e.g. “Is it just me who gets pissed off by this neologism: prosumer? Who came up with something so dumb, and why is everyone using it?”). Each group of comments consisted of 5 pages with 3 comments per page on average. Participants viewed comments for 3 and a half minutes.

After this, participants completed a narrative-based pain empathy task in which they read stories accompanied by names and faces of individuals chosen to be appropriate for the stories (either Moroccan or Caucasian adult males). Stories depicted either painful events or events that are neutral. Protagonists were described as either Arabs or Poles.

While doing these tasks, participants underwent functional magnetic resonance imaging. Before the tasks, participants completed assessments of political ideology i.e., right-wing authoritarianism and social dominance orientation (the Right-Wing Authoritarianism scale and the Social Dominance Orientation scale).

Results showed that participants reported little empathy for story protagonists who were not in pain. They felt much more empathy for protagonists of stories who were described as suffering pain. Participants reported similar levels of empathy for Polish and Arab protagonists described as suffering. Also, participants exposed to hateful comments reported similar levels of empathy as participants exposed to neutral comments.

Functional magnetic resonance imaging results indicated heightened neural activity (higher BOLD signals) in anterior cingulate cortex, anterior insula, pre- and postcentral gyrus, thalamus, caudate, supplementary motor cortex, orbitofrontal cortex, frontal pole bilaterally, and cerebellar vermis regions of the brain when participants were reading painful stories. This activity was lower in participants who previously read hateful comments than in participants who read neutral comments.

Brain activity in these regions was higher when participants read painful stories than when they read stories that were not painful. Further analysis showed that ethnicity of the story protagonist did not affect these responses.

“The results demonstrate that exposure to hate speech, even for about a quarter of an hour, affects brain response by reducing BOLD response in the region involved in mentalizing (rTPJ) while faced with the pain of others, regardless of the group membership of the protagonist (Polish or Arab),” the study authors concluded.

The study makes an important contribution to the scientific understanding of the effects of hate speech on an individual. However, it also has limitations that need to be taken into account. Notably, the number of participants of this study was small and they were young people. Additionally, their political attitudes and education had little diversity. A study on larger and more diverse groups of individuals might not yield equal results.

The study, “Exposure to hate speech deteriorates neurocognitive mechanisms of the ability to understand others’ pain”, was authored by Agnieszka Pluta, Joanna Mazurek, Jakub Wojciechowski, Tomasz Wolak, Wiktor Soral, and Michał Bilewicz.

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