Neural Insights: The Jealousy Switch

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RESEARCH UPDATE

Certain areas of the brain activate feelings of jealousy. Brain injury and stroke studies have revealed that jealousy is indeed "in your head”-specifically in the left part of the cerebral cortex. Activation or inhibition of certain regions of the brain can induce jealousy, although measures of decreased jealousy have not been recorded.

The jealous part of the brain

The cortical region of frontal lobe of the brain modulates decision-making abilities and self-control. Kelley and colleagues¹ used transcranial direct-current stimulation to target the left or right frontal cortex on two groups of healthy volunteers for a period of 15 minutes. Both groups were instructed to play a game designed to provoke feelings of rejection and then answered questions by the researchers.

It turned out that the volunteers who received stimulation to the left frontal cortex reported greater feelings of jealousy after their experience of rejection than the volunteers who received the stimulus to the right frontal cortex who were exposed to the same experience of rejection.

Othello syndrome >

Othello syndrome

There are several interesting reports of stroke patients who developed a specific kind of jealousy called Othello syndrome, which is named after a Shakespearean play. The syndrome is a type of jealousy in which people incorrectly suspect and accuse their spouse of infidelity.

Recent medical case reports describe stroke patients who exhibited almost identical symptoms of pathological jealousy in which they suddenly became jealous of other people and most notably, accused their wives of infidelity that was considered by all witnesses to be practically impossible. In one case a patient accused his wife of having an affair with his (the patient’s) childhood teacher.² In another case, a person accused his wife of having relationships with other patients in the hospital.³

All of the patients who were described as having Othello syndrome had large strokes and subsequent decrease in function of the right frontal cortex. This is interesting because the experiments in which researchers were able to produce jealousy by electrical stimulation involved over-activating the left frontal cortex.

Tendency to jealousy >

Tendency to jealousy

Since there are areas of the brain that can induce jealousy, it is likely that all humans all are born with some natural tendency to feel jealousy. Whether some people are more prone to fixating on those feelings compared with others may have something to do with a larger or more active jealousy region in the left frontal cortex of the brain. Some people, on the other hand, may have over activated the jealous regions in the brain early in life if they were constantly compared to others or if they observed jealous behavior at an early age.

While jealousy is an unpleasant fact of life, it is a painful emotion that most people would like to get rid of. Getting over such feelings is easier said than done. Envy is the world’s oldest “sin” and the most shameful of emotions because it entails feeling inferior to someone else.

However, knowing that jealousy comes from the brain may help people who are especially prone to this emotion address the problem with mindfulness strategies or by seeing a professional therapist if persistent feelings of jealously interfere with life.

References:

1. Kelley NJ, Eastwick PW, Harmon-Jones E, Schmeichel BJ. Jealousy increased by induced relative left frontal cortical activity. Emotion. 2015;15:550-555.

2. Luauté JP, Saladini O, Luauté J. Neuroimaging correlates of chronic delusional jealousy after right cerebral infarction. J Neuropsychiatry Clin Neurosci. 2008;20:245-247.

3. Rocha S, Pinho J, Ferreira C, Machado Á. Othello syndrome after cerebrovascular infarction. J Neuropsychiatry Clin Neurosci. 2014;26:E1-E2.