What Drives Us to Help Others?

By Sondra Forsyth

Most people would not hesitate to help an older or disabled person cross the street. The term for this type of action is “prosocial behavior”, which is different from altruism. The latter involves a sacrifice or a cost to the helper.

Dr. Cristina Márquez conducted a study led by Dr. Marta Moita from the Behavioral Neuroscience Lab at Champalimaud Centre for the Unknown in Lisbon, Portugal to understand how the brain generates this prosocial behavior. According to a release on the lab’s site, the team was created an experimental setup that allowed them to address this question directly in rodents. Other researchers on the team were Scott Rennie and Diana Costa.

The release quotes Dr. Márquez as saying, “In our experiment, we assigned a pair of rats different roles. One was the Helper and the other was the Partner. The Helper was free to make one of two choices. The selfish choice – opening a door where a food reward was given only to itself. Or a prosocial choice – opening another door, where both rats received a food reward. Importantly, the Helper received an identical reward regardless of whether it made a prosocial, or a selfish choice.”

The researchers found that the majority of rats favored prosocial choices. “The rats in the role of the Helper would make the choice leading to a food reward to the other about 70 percent of the time. Of the 15 rats we tested, only 1 made selfish choices consistently”, Dr. Márquez said.

Even though the Partner was not able to control the opening of the doors, it was able to demonstrate its preference towards one of them, a factor the researchers revealed to be a crucial one. “If the Partner was not reaching towards the door that led to the prosocial outcome, the Helper would not develop a preference for that side”, says Dr. Márquez. This is the first time a connection between behavioral displays of preference and prosocial choice is reported in rodents. It is comparable to the way it works with humans, if you are not asked, you may not realize that someone needs help.

However, what if someone is asking for your help, but you can see that they don’t really need it? Would you continue helping them?

To find out whether the Helper was choosing the prosocial side simply because it was following the Partner’s preference, or because they were sensitive to the rewards it received, the researchers asked what would happen if they broke the link between the Partner’s display of preference and the location of the reward. To achieve this, the team trained the Partner to demonstrate preference towards one side of the maze, even though it received a reward on both sides. “If the Partner was given a food reward on either side, the Helper disregarded the Partner’s side preference. They were making prosocial choices not only because the Partner was displaying a preference to go towards that side, they seemed to realize this display of preference was connected with the Partner receiving food.”

This finding expands a new wave of studies unraveling the complexity of social interactions in rodents. Scientists had recently discovered that rats would free a trapped partner and that they show increased pain or defense responses when witnessing partners in distress. In this new study, it is the first time scientists show that rats behave prosocially under conditions that are not stressful. “This distinction is important because it was believed that helping behavior in species other than primates was only possible under stressful conditions.”

Do these observations mean that rats share the higher values of humans, or that humans share some basic socio-biological mechanisms with rats? “Prosociality is beneficial in many situations, for both humans and rats. Simple biological mechanisms such as a positive feeling when a group member receives a reward, or being sensitive to attempts of others to achieve a goal, may benefit the individual. Humans are extremely social and we are also extremely confabulatory. So it is possible that the stories we construct about the motives to our social actions could also be explained by biological mechanisms that have evolved to keep a group of individuals cohesive”, Dr. Moita concludes.