Why Do We Hate?

Why do we hate?

Professor Robin May

Wednesday 4 March 2026

Hatred is a powerful and typically destructive emotion that is often damaging both for the target of that hatred and for the person experiencing the emotion.  So why, then, does it exist at all?

The distinction between hatred and dislike

Hatred is sometimes seen as an extension of other negative emotions such as dislike.  However, dislike is typically a passive state of aversion which focuses on avoidance (“I dislike eggs, so never eat omelettes”).  In contrast, hatred is typically more "active" and often characterized by an intense engagement with the target, usually aimed at their destruction. Very often, hatred involves a moral judgement and therefore hate is conceptually closer to emotions like contempt and disgust than to simple anger, as it involves a stable, long-term devaluation of the subject.

A “Hate Circuit” in the brain

Advances in functional Magnetic Resonance Imaging (fMRI) have suggested the existence of a specific "hate circuit" in the human brain. Individuals viewing photographs of people they ‘hate’ (as opposed to those whom they feel more neutral about) show specific activity in a number of brain areas, most notably the putamen and the insula.

The putamen is a region associated with the planning of motor movement, suggesting that hatred prepares the body for action. Interestingly, both the putamen and insula are also activated by romantic love. However, there is a crucial difference: while love tends to "deactivate" the regions of the frontal cortex responsible for judgment and critical thinking, hatred leaves these areas fully functional. This allows a person to remain coldly rational and calculated in how they act against the object of their hate, whereas a person in love is often said to be "blind" to the faults of their partner.

The evolutionary basis for hatred 

At first glance, it is difficult to imagine how such a destructive emotion may have evolved.  However, the frequent association of hatred with group identities suggests that it may have served as a mechanism for group survival in the face of aggressive threats from outsiders.

For most of our existence, humans have lived in small, tight-knit tribes where survival depended on in-group cohesion. Conversely, ‘out-groups’ often represented a threat either directly (through violence) or indirectly (through competition for resources).  Consequently, many of the most distressing examples of hatred that we see today represent an extreme extension of this behaviour, in which specific groups attach strong negative emotions to those individuals who look or behave differently from their own group.

This ‘out-group hatred’ appears to also occur in our closest relatives, the chimpanzees.  During the 1970s, Jane Goodall documented the Gombe Chimpanzee War, a four-year conflict between two rival chimpanzee communities that had previously been part of the same group. The "Kasakela" community systematically stalked and killed every male member of the "Kahama" splinter group. These attacks were not spontaneous outbursts of rage but were often calculated, "border-patrol" style raids where groups of males would gang up on isolated individuals. This suggests that the capacity for tribalism and lethal out-group aggression is a trait shared by the common ancestor of humans and chimpanzees…although of course it remains impossible for us to assess whether Kasakela chimps truly ‘hated’ those from the Kahama group.

Can we ‘cure’ hatred?

Given the overwhelmingly negative impact of hatred worldwide - from minor playground aggressions to national acts of genocide – strategies to prevent or ‘treat’ hatred are desperately needed. 

Since hatred frequently depends on a sense of ‘other-ness’, by far the most successful way to tackle it is to encourage empathy and understanding between ‘hater’ and ‘hat-ee’.  Whether that is through one-to-one counselling to help with a particularly bitter divorce or social dispute, or large-scale social interventions to bring different groups together and help overcome religious or racial intolerance, methods that stimulate us to see our similarities, instead of our differences, have had a real impact in reducing the violent consequences of hatred. 

However, the problem with such interventions is that they are slow, costly and require constant reinforcement, which has led to intense interest in the idea of finding ‘quick fix’ solutions based on chemical signalling.  In some animals, volatile molecules released in urine or other fluids can provoke responses ranging from sexual receptivity to potent aggression.  Whilst there is little evidence for significant pheromone signalling in humans, recent research has identified specific compounds that do apparently modulate human hostility. For instance, the human body volatile hexadecanal (HEX) has been found to have a sex-dependent effect, reducing aggressive behaviour in men while increasing it in women.  Similarly, the scent of human emotional tears appears to contain a chemosignal that significantly reduces male aggression. Brain scans showed that sniffing tears reduced activity in the brain's "aggression network" (the prefrontal cortex and insula) when men were provoked.

So who knows?  Perhaps, in the future, we may be able to harness these chemical "brakes" to help reduce hatred behaviours in certain settings and maybe even unlock a utopian future of universal tolerance and respect.  For now, though, the best way to tackle hatred is the tried-and-tested approach of pausing, taking a breath and trying and put yourself in the other person’s shoes…

© Professor May 2026

References and Further Reading

• Zeki S, Romaya JP. (2008) "Neural Correlates of Hate." PLoS ONE. An open-access study identifying the brain's hate circuit.
• Mishor E, et al. (2021) "Sniffing the human body volatile hexadecanal blocks aggression in men but triggers aggression in women." Science Advances.
• Shani A, et al. (2023) "A chemical signal in human female tears lowers aggression in males." PLOS Biology.
• Grigoryan L, et al. (2023) "Helping the ingroup versus harming the outgroup." Journal of Experimental Social Psychology.
• Gombe Chimpanzee War - Wikipedia