Chimps get angry, not spiteful
2007-07-17 07:27
London - An angry chimpanzee will
take revenge but - unlike a human - it will not do so out of
spite, according to a study published on Monday that offers
insights into how people perceive what is fair.
The study showed chimpanzees would seek retribution when
wronged but did not punish others out of spite, for instance if
another chimpanzee was better off, said Keith Jensen, an
evolutionary biologist at the Max Planck Institute in Germany,
who led the study.
Scientists had debated whether a sense of fairness and
social comparison applied only to humans and the study was an
attempt to answer some of the questions, Jensen said.
"Like humans, chimpanzees retaliate against personally
harmful actions, but unlike humans, they are indifferent to
simply personally disadvantageous outcomes and are therefore
not spiteful," he and colleagues wrote in a study published on
Monday in the Proceedings of the Natural Academy of Sciences.
The study suggests that anger is an important motivational
force but what causes it differs greatly between chimpanzees
and humans, Jensen said.
"Humans and apes both get upset at theft but humans are
more likely to get upset at unfairness," he said.
The researchers explored how chimpanzees responded to loss
and theft by putting them one at a time in a small room with
access to food on a sliding table in a booth outside.
Each animal held a rope allowing it to collapse the table
and send the food out of reach. Unsurprisingly, the chimpanzees
chose not to collapse the table while eating, researchers said.
When the researchers made the food on the table viewable
but out of reach to the first chimpanzee or when a second animal
could eat in plain view of the first, the chimpanzees did not
seem to care.
When the second animal was able to take the food away from
the first, the chimpanzee without food often collapsed the
table to take revenge, the researchers said.
"The final situation was punishment where theft was
involved," Jensen said.
"The only
option for the victim in this situation was to collapse the
table and nobody eats."