Download Is altruism encoded in our genes

Is altruism encoded in our genes?
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New studies suggest chimpanzees may also be altruistic.
By William Orem
(July 4, 2006)
Caring more: Studies show chimps can be altruistic.
(Photo: Lea Maimone/Morguefile)
The ability to think selflessly has been taken for some time to represent a specifically human trait. Although it’s true
that domestic animals demonstrate affection and may even come to an owner’s aid, researchers working on altruism
are wary of drawing broad conclusions from such events.
A technical definition of altruism might include, for example, a willingness to provide help without either the
experience or expectation of reward — conditions difficult to replicate even in a laboratory setting.
Altruism may also require a complex of fairly high-level cognitive abilities, such as intentional state attribution, which
involves the recognition that an entity other than oneself seeks to fulfill a plan. The presence of such skills in
nonhuman species is not clear.
A study recently conducted at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, however,
says that altruistic impulses may exist in primates other than humans. It also brings to light some surprising
information about human altruism: It appears even in prelinguistic toddlers.
“It was surprising to us that this was so obvious at this early age,” said Felix Warneken, co-author of the study with
Michael Tomasello. Warneken and Tomasello observed both children and chimps in various situations where the
possibility of giving aid arose. While hanging a sheet on a line near their subjects, the experimenter would suddenly
drop a peg out of reach. For 10 seconds he reached unsuccessfully for the peg. After that he would initiate eye
contact and, after another 10 seconds, use the vocalization: “My peg!” In 84 percent of the human cases, toddlers
assisted the experimenters in retrieving the item even before eye contact was established.
Surprisingly, chimps in similar situations demonstrated a helping response as well. They not only tended to aid their
caretaker in retrieving dropped objects but were also more likely to do so when the caretaker reached for the item,
evincing a need. In no instance was the helping behavior met with a reward.
It is here, though, that wariness about drawing broad conclusions comes into play.
“The [Warneken and Tomasello] papers show that chimps sometimes provided instrumental help to adults that they
knew very well,” said Joan Silk, an anthropologist at UCLA and the author of numerous studies on the evolution of
primate behavior. “This is very interesting, and well worth reflecting on. However, it is not clear from these
experiments what motivated the chimps to behave the way that they did. Were they motivated out of concern for their
caretakers? Did they perceive this as a game or a chore? Had they been asked before to retrieve items and been
rewarded for this? Had they been conditioned to please human caretakers?”
Warneken said he is aware of this type of concern.
“It could be these kinds of behaviors are confined to a relationship with a person they know well,” he said. “We are
currently studying other chimpanzees to see whether they help a human they never interacted with before.”
The distinction may well be a significant one, as the human children showed a robust tendency to help even
strangers. Although by no means ubiquitous, this predilection to aid strangers is generally found in human adults.
Individual instances include a passer-by automatically stooping to help up a senior citizen who has fallen. Group
examples include blood drives, food drives and the willingness of large numbers of people to donate resources to the
victims of natural disasters in other countries. Indeed, to many the stipulation that giving occur between strangers is a
prerequisite for true altruism.
Warneken and Tomasello’s data are only the beginning of a new picture, but they are suggestive of a model whereby
predisposition to pro-social behavior — even toward strangers — is hard-wired into at least some primates.
This model, in turn, would point toward a much more ancient pedigree for altruism than was formerly believed,
reaching as far back as the common ancestor between humans and chimps. If so, that would mean a basic form of
altruism has existed not for tens, or even hundreds of thousands of years, but for some six million.
“[Recent] studies seemed to indicate that helping behaviors in general were totally human-specific,” Warneken said.
“Now it seems the question is open again. The roots of altruistic behavior seem not to originate in humans only but go
further back in evolutionary time.”
Is selflessness even possible?
The hypothesis comes with strings attached, however, as evolutionary biologists have had a difficult time imagining
how true selflessness could have come about. Phylogenetic models recognize the pressure that favors selfish action.
It is self-directed behavior in general that links with survival and thus can be translated into heritable traits. In short, a
tendency to give away one’s food to strangers, exert one’s energy to benefit strangers and cede reproductive
opportunities to strangers should soon disappear.
Nevertheless, natural selection works on the gene pool, not the individual. This distinction has led some researchers
to suspect roundabout mechanisms by which selflessness may become encoded by virtue of being beneficial to
multiple parties. One form of such an arrangement is reciprocal altruism, in which giving is linked to getting.
“I believe the [behaviors] glossed by ‘reciprocal altruism’ were favored by natural selection and so, in some sense,
‘selfish,’” said James Moore, an associate professor of anthropology at the University of California, San Diego. “The
caveats are that this says nothing about the emotional or cognitive experience of ‘selfishness’ and that ‘selfish origin’
can include original payoffs to offspring or other kin.”
In other words, genetic analysis leaves aside the issue of whether we feel such behavior is “good” and asks only how
it might have evolved. In this light, a father who deprives himself of something to benefit his daughter still increases
the likelihood that his own genetic material will continue on, and so is behaving selfishly in an evolutionary sense.
One would expect this kind of concern for kin welfare to become encoded, and more complex feedback loops may
well have evolved that encompass strangers in a similar way.
Is selflessness social?
Another possibility is that altruism may represent an emergent property of social groups, one that is pinned only to
genetics in terms of a predisposition. Such an option would allow for higher-level reinforcement of pro-social behavior
among species with sophisticated social networks. Such selective pressure would occur late in the evolution of the
species, “but not so late that there might not have been further genetic selection favoring tendencies toward altruism,”
Moore said.
“An important angle on this is that I agree with Darwin’s initial idea that the levels of altruism that we see in humans
are likely to have evolved through group selection,” he added. “In that sense, altruism would be a genetically
grounded emergent property of groups.”
Warneken allows for this possibility as well. “Humans at least developed cultural systems in which altruistic behaviors
are sustained and asocial behaviors are punished, and these groups then have advantages over other cultural
groups,” he said.
Silk places particular emphasis on the social dimension and its connection to humanness.
“When animals cooperate in a strictly contingent way — I’ll scratch your back, if and only if you scratch mine — then
self-interest provides a sufficient explanation for the behavior,” she said. “That is, self-interest alone would be enough
to produce this kind of reciprocal cooperation.” However, she added, the data does not demonstrate an obvious
preponderance of this “contingent reciprocity” in nonhuman primates. It is an absence that may point toward the
importance of more complex forms of sociality.
“My work on the social behavior of baboons convinces me that the most profound link between human and
nonhuman primates is the fundamental importance of social bonds,” she said. “We now have evidence that female
baboons form close, stable and egalitarian social bonds with other females and that females who are most socially
integrated enjoy reproductive advantages. For both humans and other primates it seems crucial to be part of welldefined social networks and to live in a social world.”
The quest to understand that social world of primates goes on, a quest that is ultimately about understanding both
what ties us to other species and what makes us unique. “More than other primates, humans seem to have evolved
the capacity for real concern for the welfare of others, a concern that is reflected in our capacity for friendship, our
preference for fair outcomes and our willingness to make sacrifices on others’ behalf,” Silk said.
William Orem is science editor at Science & Theology News.