What exactly is hate? Which parts of the brain are involved? Is there a neural relationship between hate and love? Find out in this article.
You have probably heard it said that there is a fine line between love and hate. This implies that it is extremely easy to move from one state to the other. But is this true?
Indeed, neuroscientific advances in love and hate research suggest that some cortical and subcortical structures activated for hate are also activated for love.
Using functional magnetic resonance imaging, neuroscientists Zeki and Romaya (2008) studied 17 people who harbored hatred for someone. They observed that structures such as the putamen and insula were activated for stimuli associated with both hate and romantic love. Their findings provided a basis for exploring feelings of hatred in the brain.
Hate has been addressed in many ways. It can be seen as an emotional attitude, a normative judgment, an emotion, a motivation or a generalized evaluation. However, despite conceptual differences, one component of hatred is universally recognized: the desire to harm. This desire can be a goal or an end in itself.
Individuals may desire to harm others in order to restore the established order, to elevate themselves, to assert their ego, to gain pleasure, to regain autonomy, or to prevent abandonment. In all these cases, whatever the intention, the ultimate goal is to cause harm.
At the interpersonal level, hatred fulfills different functions. For example, self-repair, revenge, communication of emotional states or reaffirmation of autonomy. At the intergroup level, hatred has been recognized as a functional tool for political behavior, such as connection and cohesion within a group.
Although hate is influenced by other emotions such as anger, dislike and contempt, it should not be equated with them. In fact, one study found that hate is more arousing than these three emotions and is closer to disgust and contempt than to anger and disgust.
Hate and the brain
Using functional magnetic resonance imaging, researchers found that different brain structures are activated when a person sees a photo of someone they hate. In one study, they scanned the brains of 17 people. The participants looked at faces of people they hated, as well as faces of acquaintances with whom they had neutral feelings.
The results of the study showed that when participants looked at a face they hated, activity increased in the medial frontal gyrus, right putamen, premotor cortex, frontal lobe and medial insula.
Three areas were also found where activation was linearly related to the level of hatred in the brain. These were the right insula, right premotor cortex and right frontal medial gyrus. An area of deactivation was also detected in the right superior frontal gyrus.
This research showed that there is a pattern of hate activity in the brain. The pattern is different from the one associated with romantic love. However, the two share two areas in common: the putamen and the insula.
Medial prefrontal cortex
The activation of this cortical region plays a highly relevant role in the task of making inferences about others. It is involved in reasoning and its activation increases when you think about yourself, your family or someone you care about (Morgado, 2019).
The prefrontal cortex is also activated when you think about people who share your ideals. However, its activation decreases when you think about people who don’t think the same way or are indifferent to you.
The prefrontal cortex also becomes less active when you see people you think are less intelligent and emotional. This deactivation can also affect the empathy (or lack of it) you may feel towards someone you hate. In fact, when a person observes another person’s emotional state, regions such as the medial prefrontal cortex, temporoparietal junction, superior temporal sulcus and temporal pole have been shown to be activated. This suggests that the medial prefrontal cortex may be highly involved in both empathy and theory of mind (Gallagher and Frith, 2003).
Since activation of the medial prefrontal cortex decreases when you think about people you hate, it should not surprise you that you feel little empathy for them. This is because empathy depends on the activity of this cortex, among other things.
Hate circuitry in the brain
The putamen and insula are brain structures involved in the perception of contempt and disgust. These two structures, and others we have already mentioned, make up what can be called the hate circuit.
This circuit involves both cortical and subcortical structures. It is key to generating aggressive behavior and translating it into action through motor planning. The circuit also includes a portion of the prefrontal cortex, which is thought to be essential for predicting the actions of others (Morgado, 2019).
Subcortical activity involves the two different structures we mentioned earlier: the putamen and the insula. The former is involved in the perception of contempt and disgust. It is also involved in learning, motor control, speech articulation, reward and cognitive functioning (Ghandili & Munakomi, 2021).
The insular cortex has several functions:
- Sensory processing.
- Representation of emotions and feelings.
- Autonomic and motor control.
- Risk prediction and decision-making.
- Body and self-awareness.
Hate involves parts of the brain that developed at different stages of our evolution as a species. In fact, our ability to experience such emotions can be traced back to when the first modern humans emerged.
In this context, hatred was an adaptive strategy. It made it easier to survive in the midst of other groups competing for natural resources.