Altruism
'in-built' in humans
By Helen Briggs
BBC News science reporter
March 5, 2006
These children are so young - they still wear diapers and are barely
able to use language, but they already show helping behaviour
Felix Warneken
Infants as young as 18 months show altruistic behaviour, suggesting
humans have a natural tendency to be helpful, German researchers have
discovered.
In experiments reported in the journal Science, toddlers helped
strangers complete tasks such as stacking books.
Young chimps did the same, providing the first direct evidence of
altruism in non-human primates.
Altruism may have evolved six million years ago in the common ancestor
of chimps and humans, the study suggests.
Just rewards
Scientists have long debated what leads people to "act out of the
goodness of their hearts" by helping non-relatives regardless of any
benefits for themselves.
Human society depends on people being able to collaborate with others -
donating to charity, paying taxes and so on - and many scientists have
argued that altruism is a uniquely human function, hard-wired into our
brains.
The latest study suggests it is a strong human trait, perhaps present
more than six million years ago in the common ancestor of chimpanzees
and humans.
"This is the first experiment showing altruistic helping towards goals
in any non-human primate," said Felix Warneken, a psychologist at the
Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.
"It's been claimed chimpanzees act mainly for their own ends; but in
our experiment, there was no reward and they still helped."
'Astonishing'
Dr Warneken and colleague Professor Michael Tomasello wanted to see
whether very young children who had not yet learned social skills were
willing to help strangers.
The experimenters performed simple tasks like dropping a clothes peg
out of reach while hanging clothes on a line, or mis-stacking a pile of
books.
Nearly all of the group of 24 18-month-olds helped by picking up the
peg or the book, usually in the first 10 seconds of the experiment.
They only did this if they believed the researcher needed the object to
complete the task - if it was thrown on the ground deliberately, they
didn't pick it up.
"The results were astonishing because these children are so young -
they still wear diapers and are barely able to use language, but they
already show helping behaviour," said Felix Warneken.
Lost spoon
The pair went on to investigate more complicated tasks, such as
retrieving an object from a box with a flap.
Children and chimpanzees are both willing to help, but they appear to
differ in their ability to interpret the other's need for help in
different situations
Warneken at al
When the scientists accidentally dropped a spoon inside, and pretended
they did not know about the flap, the children helped retrieve it. They
only did this if they believed the spoon had not been dropped
deliberately.
The tasks were repeated with three young chimpanzees that had been
raised in captivity. The chimps did not help in more complex tasks such
as the box experiment, but did assist the human looking after them in
simple tasks such as reaching for a lost object.
"Children and chimpanzees are both willing to help, but they appear to
differ in their ability to interpret the other's need for help in
different situations," the two researchers write in Science.
Ugandan study
Further evidence of chimps' ability to cooperate was revealed in a
separate study published in the same edition of the scientific journal.
Alicia Melis, at the Ngamba Island Chimpanzee Sanctuary in Uganda,
found that chimps recognised when collaboration was necessary and chose
the best partner to work with.
The chimps had to cooperate in reaching a food tray by pulling two ends
of a rope at the same time.
"We've never seen this level of understanding during cooperation in any
other animals except humans," she said.
But she said there was still no evidence that chimpanzees communicated
with each other about a common goal like children do from an early age.