Had a weird situation recently in which a male friend’s girlfriend was behaving strangely toward me. I think she was jealous. How uncomfortable and embarrassing for both of us.

In this case her defence mechanisms were being sorely misused; any perceived threat from me was plainly imaginary.

Make no mistake: jealousy (not to be confused with envy or covetousness) can be  extremely harmful to the self and relationships. 

On the other hand, human behaviour isn’t always innocent, and the possessive impulse, scientists say, also serves an evolutionary purpose. Aren’t we strange beasts?

What the experts say 

“Everybody has experienced jealousy, so there must be neuro-cognitive priming for it. Jealousy involves a triadic situation. In infancy, it involves the relationship between the infant and the loved one, between the mother and the rival, and between the infant and the rival. I tested three- and six-month-olds. I talked to the baby with the mother in sight. She interrupted us, and then I either engaged the mother in a very excited dialogue to the exclusion of the baby or talked to the mother while she just looked at me. Only during the dialogue condition did the baby become upset. The monologue condition was not threatening. Jealousy is closely related to survival.” 

MARIA LEGERSTEE, professor of psychology, Infancy Centre for Research, York University, Toronto 

“Jealousy is adaptive to a point, because it helps orient people to one another and protect their relationship from outside interlopers. But it’s a problem if the alarm is going off too much. You have to be able to argue against the feeling by considering alternative interpretations of what’s happening. Are you sounding the alarm pre-emptively because you’re trying to prevent something that could happen down the line? That doesn’t work, because the more you sound that alarm, the more tension it causes in your relationship. It’s a feedback loop. Solidify the relationship rather than defend it.”

CARL HINDY, clinical psychologist, co-author, If This Is Love, Why Do I Feel So Insecure?, Nashua, New Hampshire 

“Jealousy has several evolved functions, including sensitizing us to signals of infidelity or defection, prompting action to curtail interactions with potential rivals, motivating actions such as threats or violence to fend off mate poachers, increasing our efforts to fulfill a partner’s desires and preventing defection from a relationship. Too much jealousy can be destructive, and is the leading cause of spousal violence and murder. The one function that might be less relevant today is increasing a man’s certainty in paternity. Nonetheless, studies of genetic cuckoldry using DNA fingerprinting show a rate of about 12 per cent.”

DAVID BUSS, professor of evolutionary psychology, University of Texas, Austin, author of The Dangerous Passion

“Sometimes a threat is real, and sometimes it’s our own insecurities and we sabotage the relationship. We actualize our biggest fear because we lack self-empowerment and don’t know what we uniquely bring to the table. We let our imagination move toward the sinister and become ‘mind-readers,’ imagining that we know what everyone is thinking. I would worry not about the relationship that is being sabotaged, but about my relationship with myself. When you develop a positive, witty, compassionate demeanour, people want to be with you and you don’t feel like you have to hold on so tightly to everything.”

DEBBIE MANDEL, stress management specialist, author, Addicted To Stress, Lawrence, New York