A new study shows that rats are more likely to help those of their own which do them greater favours with a better-quality help than those giving less than that.
Humans as well as other animals have developed the art of cooperative behaviour whereby one reciprocates help given by another. We have learned to return the favour. Humans have, however, displayed this ability better than other species. Some of us give as much as they receive, while others give better and more.
What about the quality of reciprocal behaviour, among other animals, if the service of one is better than that of another? A new study has put this aspect of cooperation among animals into perspective: Norway rats were used as subjects and they demonstrated that they, in such cases, only give as well as they have themselves received.
Experts affirm that reciprocity among other species is a rare occurrence. But, at the same time, our methodologies of quantifying the costs and benefits are difficult to devise. An alternative method to the ones of the past has been used in the new study.
Rats were trained to pull on a stick that would bring some food within the grasp of a rat located in an adjoining cage. Thereafter, a rat was put in a cage with other rats in cages on both of its sides. On one side, a rat would pull a stick that provide carrot pieces to the rat in the central position. Then, the latter was given the chance to return the favour to his fellow rats; it was equipped with the same apparatus as the others.
The carrot was sometimes switched with a banana, for which the rats seemed to have a greater liking. As such, the rat providing the banana to its fellow rats would be regarded as the superior partner. The scientists observed that the focal rat would be more readily helpful to their superior friends as opposed to those which would provide them with carrots.
It seems that rats having brought forth “better help” later received better rewards.
Upon evaluating this behaviour, the scientists concluded that this is cognitively demanding for animals, since they have to keep reminding themselves of who did what and having to make do with their judgement skills.
The rats in the study were able to recall the quality of the help they received together with the one behind the superior help. They were also able to tune their behaviour in accordance with their observations. It seems that rats are more inclined to helping one of their own that has helped them before than one which has not helped them at all.
The research of the authors of the paper, Vassilissa Dolivo and Michael Taborsky, supports the opinion that animals can make their way about reciprocity, co-operating conditionally and providing better treatment to those giving better quality help.