Do Animals Fall Prey to the Green-Eyed Monster?

Why do you think Scar resented Mufasa in ‘The Lion King’? Was it because he was jealous? It might work that way in fiction. But, in the non-fictional animal world, how appropriate is the word ‘jealous’?

(Jealousy, needless to say, is a complex emotion that evolved to protect social bonds from interlopers. It is a relatively common human behaviour often encountered among circles of friends, family and colleagues. But, do animals too get possessive and green-eyed?

If you’ve got a pet dog, you would supposedly claim that your puppy acts weird when you don’t give him the attention he desires or cuddle a different pet. You could probably associate this behaviour of your pet to those observed in children aged under two.)

A study carried out by psychologists Christine Harris and Caroline Prouvost at the University of California, San Diego, identified that infants manifested a non-verbal form of jealousy. The babies displayed more negative reactions when their mother interacted with another infant than when the mother paid attention to a book. Analogously, dogs showed more aggressive behaviour, through biting and snapping, when their master petted a dog-like-toy. But such aggression was not observed when their owners interacted with a non-sociable object.

To quote the lead researcher Professor Christine Harris, “Our study suggests not only that dogs do engage in what appears to be jealous behaviours, but also that they were seeking to break up the connection between the owner and a seeming rival.”

Another commonly found behaviour in many animals, including birds, insects, fish, and mammals, is ‘mate guarding’. It is the physical guarding of the females from the rival males and has been traditionally interpreted in the context of sexual conflict. This behaviour has been recorded in yellow dung flies and soapberry bugs.

Coppery titi monkeys, a monogamous primate species, have also been found to evince jealousy. In the presence of a potential romantic corrival, the male titi monkeys tend to get more competitive and occasionally try to impede their mates from moving towards the intruder.

In an additional experiment, the male titi monkeys were allowed to watch their mates interact with stranger males. When observing their mates, the monkeys showed increased levels of hormones like testosterone and cortisol. Further observations showed elevated activities in the cingulate cortex region in the brain, which is associated with the feeling of social exclusion in humans.

For an animal to get jealous, they need to have the cognitive ability to identify a potential intruder who bears potential threats to their relationship with their mates. This is a tall order for most of the animals. However, various researches have proven that some animals exhibit jealousy induced behaviours, which can’t be overlooked either.

But it is also significantly plausible that we are just being anthropomorphic and trying to project human emotions onto rather uncomplicated, simple animal behaviour.

Figure 1. If jealousy had a face then it would be this

Figure 2. Master playing with toys vs Master playing with another dog

Figure 3. A possessive coppery titi.