According to a new study led by Professor Karen Bales at the University of California, humans are not the only species that get jealous. Monkeys can also experience Jealousy, and Scientists know which part of the brain is responsible for producing this emotion. It is highly likely that this carries over into humans as well.

Scientists believe that further study into the neuroscience behind jealousy will help people to better control it in the future. What makes people jealous is an incredibly broad spectrum. In romantic relationships, a bit of jealousy is considered to be socially acceptable.

However, in platonic relationships, it is considered pathological.

Titi monkeys

Bales began to research jealousy in male coppery titi monkeys with the hopes of gaining a better understanding of the intense emotion. Titi monkeys form long-term relationships with one partner. They show specific signs of distress when they are separated from their partners, and they are known to be very protective of their mates. Male titi monkeys have even been seen to physically hold their partners back from interacting with other males.

The research

The study was published in "Frontiers in Ecology and Evolution" and showed the findings of which part of the brain produces the emotion of jealousy.

Male titi monkeys were separated from their female partners and caged.

They were made to watch as other males were introduced to the females. Researchers also had the males watch unfamiliar females with unfamiliar males.

Using PET and MRI scans, scientists were able to measure the brain activity. Male titi monkeys who were forced to watch their female partners with other males showed much higher levels of cortisol, which is a stress hormone.

Scientists also saw an increase in testosterone. The longer they were made to watch, the higher the cortisol levels rose.

Scientists compared these results to the results of the monkeys who watched two unfamiliar monkeys. It was found that the titi monkeys who watched their mates with other males showed higher uptakes in three parts of the brain for sugar consumption.

The cingulate cortex, the part of the brain associated with social pain, showed the most significant results. Scientists concluded that the cingulate cortex is the part of the brain that produces jealousy, which is often linked to social rejection.

The results

Bales concluded that there must have been a convergent evolution between pair bonding and jealousy in the terms of neurochemistry. Monogamy is an evolved concept with correlating neurobiology that differs from species to species. Scientists have also performed the same experiment on rodents, resulting in similarities and differences.

Scientists are continuing research in order to identify receptors for the hormones vasopressin and oxytocin in an attempt to control excessive jealousy. However, they are a long way from human trials. Bales believes it will be difficult to induce jealousy on humans who are aware that they are part of an experiment.