London, June 5
Ever wondered why we often help
others even without expecting anything in return? That could be thanks
to simple biological mechanisms that have evolved to keep a group of
individuals cohesive, says a new study.
"We would not hesitate
about helping an older person trying to cross the road. This type of
actions is called pro-social behaviour," said researcher Cristina
Marquez from Champalimaud Centre for the Unknown, Lisbon, Portugal.
The researchers studied rats' behaviour to observe pro-social decisions under laboratory conditions.
The
researchers emphasised that the kind of behaviour they studied was
different from altruistic acts, which involve a sacrifice, or a cost, to
the helper.
"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
pro-social choice: Opening another door, where both rats received a food
reward," Marquez said.
The Helper received an identical reward regardless of whether it made a pro-social, or a selfish choice.
The researchers found that the majority of rats favoured pro-social 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 one made selfish choices consistently," Marquez 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.
Do these
observations mean that rats share the higher values of humans, or that
humans share some basic socio-biological mechanisms with rats?
"Pro-sociality
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," said study leader Marta Moita.
"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," Moita said.
