sciencedaily | A group of researchers from Switzerland, Germany, Austria, Italy and
Great Britain, headed by anthropologist Judith Burkart from the
University of Zurich, therefore developed a novel approach they
systematically applied to a great number of primate species. The results
of the study have now been published in Nature Communications.
For their study, Burkart and her colleagues developed the new
paradigm of group service, which examines spontaneous helping behavior
in a standardized way. With the aid of a simple test apparatus, the
researchers studied whether individuals from a particular primate
species were prepared to provide other group members with a treat, even
if this meant missing out themselves (see box). The scientists applied
this standardized test to 24 social groups of 15 different primate
species. They also examined whether and how kindergarten children aged
between four and seven acted altruistically.
The researchers found that the willingness to provision others varies
greatly from one primate species to the next. But there was a clear
pattern, as summarized by Burkart: “Humans and callitrichid monkeys
acted highly altruistically and almost always produced the treats for
the other group members. Chimpanzees, one of our closest relatives,
however, only did so sporadically.” Similarly, most other primate
species, including capuchins and macaques, only rarely pulled the lever
to give another group member food, if at all – even though they have
considerable cognitive skills.
Until now, many researchers assumed that spontaneous altruistic
behavior in primates could be attributed to factors they would share
with humans: advanced cognitive skills, large brains, high social
tolerance, collective foraging or the presence of pair bonds or other
strong social bonds. As Burkart’s new data now reveal, however, none of
these factors reliably predicts whether a primate species will be
spontaneously altruistic or not. Instead, another factor that sets us
humans apart from the great apes appears to be responsible. Says
Burkart: “Spontaneous, altruistic behavior is exclusively found among
species where the young are not only cared for by the mother, but also
other group members such as siblings, fathers, grandmothers, aunts and
uncles.” This behavior is referred to technically as the “cooperative
breeding” or “allomaternal care.”
The significance of this study goes beyond identifying the roots of
our altruism. Cooperative behavior also favored the evolution of our
exceptional cognitive abilities. During development, human children
gradually construct their cognitive skills based on extensive selfless
social inputs from caring parents and other helpers, and the researchers
believe that it is this new mode of caring that also put our ancestors
on the road to our cognitive excellence. This study may, therefore, have
just identified the foundation for the process that made us human. As
Burkart suggests: “When our hominin ancestors began to raise their
offspring cooperatively, they laid the foundation for both our altruism
and our exceptional cognition.”
