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JASs forum
Journal of Anthropological Sciences
Vol. 85 (2007), pp. 237-239
the JASs is published by the Istituto Italiano di Antropologia
Ethics and Altruism
Altruism in human and non-human animals
Augusto Vitale & Enrico Alleva
Section of Behavioural Neuroscience, Dipartimento di Biologia cellulare e Neuroscienze, Istituto Superiore
di Sanità, Viale Regina Elena 299 – 00161 Roma
Altruism in non-human animals
It is called altruistic any behaviour that
increases the chances of survival and/or
reproduce of the receiver, to the disadvantage of
the altruist. Altruism is an interesting theoretical
problem because, apparently, it appears to be
in contradiction with the Darwinian theory of
natural selection. As a matter of fact, this theory
suggests that for each individual those characters,
including behavioural ones, which improve the
individual’s chances to survive and reproduce
are favoured (individual fi tness). How then is
it possible that behaviours which penalise the
individual displaying them, and favour other
individuals, can be positively selected?
ere exist in nature diff erent examples of
altruistic behaviours in diff erent zoological taxa.
For example, altruistic behaviour can be found in
diff erent species of birds nesting on the ground: in
these species when a potential predator approaches
the nestlings in the nest, the adults move away
and, faking a physical handicap, attract the
attention of the predator away from the nestlings.
Another example come from male baboons, that
form temporary alliances to overcome another
male interested in a female in oestrus.
Diff erent hypotheses have been formulated
to explain the apparent evolutionary paradox
represented by altruistic behaviour.  e rst
hypothesis can be labelled as “kinship selection”,
which explains altruistic behaviours aimed at
relatives.  e social insects, the hymenoptera,
represent the classic example. Hamilton has
originally proposed this hypothesis in the early
‘60s, in the eff ort of fi nding a gene-based theory,
which could explain the existence in these insects
of sterile castes (Hamilton, 1964).  en, this
theory has been expanded to diff erent kinds of
animals as well, in the cases in which an altruistic
behaviour allows the survival of a number of
individuals genetically related with the altruist,
and therefore carrying part of the same genes
(inclusive fi tness). Among other ideas, this theory
was also one of the fundamental pillars of a new
discipline called “sociobiology”, which developed
in the second half of the 70’s (Wilson, 1975).
Altruism in non-human primates
Non-human primates, being phylogenetically
closer to humans than any other animal,
represent very interesting and promising subject
for the study of altruistic behaviour.  ese
animals, perhaps, are the ones that can help us
to better elucidate possible evolutionary paths,
that lead to the manifestation of some human
behavioural traits. We have mentioned above
examples of altruistic behaviours in diff erent
animal, but in the cases mentioned the altruist
appears, directly or indirectly, to be rewarded in
some way for his altruistic act. We can think of
examples in humans of true altruistic behaviours,
that is, completely unselfi sh acts for somebody
else’s benefi t. Do cases of “true altruism” exist in
non-human primates? Studies carried out, for
example, in chimpanzees can provide us with
elements for discussion. In a study by Warneken
and colleagues, semi-wild chimpanzees helped
unfamiliar humans to reach a stick, with no
apparent reward (Warneken et al., 2007).
238 JASs forum: Ethics, Altruism and Evolution
A possible interpretation of the results observed
could be that captive chimpanzees associate
humans with food rewards, as a result of a
generalised experimental protocol. However,
Warneken carried out another experiment,
in which chimpanzees had to choose whether
to help or not unrelated chimpanzees to
unchain a door.  e results showed that
chimpanzees signifi cantly choose to help their
conspecifi cs.  ese results were in contrast with
results obtained in other laboratories, where
chimpanzees did not help each other.  erefore,
chimpanzees appear to be able to engage in
altruistic behaviours similar to those we would
expect in the case of true altruism, but the
possibility for these behaviours to be shown
depends on individual diff erences, context and
history of that particular group of animals.
For example: how the experimental history
of that particular colony of captive primates
do infl uence its behaviour, in relation to the
expectation of obtaining care and rewards?
Obviously, data from natural populations are
needed. Frans de Waal, rightly so, affi rms that
in captivity animals display more spontaneous
altruistic behaviours because they are relatively
freer from the necessities and perils of life in
the wild. We could also add that in captivity,
as mentioned before, there is more opportunity
to learn the association between a certain act
and the consequent reward. Having said that,
data do exist of what seems to be true altruism
in nature, but they could have to do with the
reward of improving the altruist’s social status
and reputation within a social group (de Waal,
2006). So, is this true altruism?
The evolution of altruism in the
human primate
What are the implications of the study of
altruism in animals for the understanding
of altruistic behaviours in humans? We feel
that it very much depends on how we want
to interpret our behaviour.  e study of
cooperation and altruism in humans is an area
of research where, potentially, the personal
belief and the point of view of the researcher
on how society should be can potentially detract
from the objectivity of the scientifi c results.
As a matter of fact, as de Waal indicates,
two are the major theories regarding human
nature.  e rst one, called “the veener theory”
regards humans as inherently selfi sh, where
ethics helps humans to keep the nastiness of
the evolutionary process at bay (Huxley, 1894,
reprinted in 1989).  e other theory sees humans
as naturally inclined toward cooperation and
altruism.  e reason beyond the latter theory is
that cooperation is considered an essential part
of a functioning social system. Non-human and
human primates are both characterised by highly
complex social system, which can better function
when cooperation plays an important role in the
relations among its members.  e mechanism
which allows the onset of cooperation and
altruism is considered to be “empathy” (de Waal,
2006), that is, the possibility to perceive the
state of diffi culty or negative condition in which
a conspecifi c fi nd itself in a particular moment.
is need to keep together the members of a
complex social system through cooperation and
altruism, mediated by empathic capabilities is,
in our opinion, a convincing argument in favour
of an evolutionary continuity between humans
and non-humans for what concerns altruistic
behaviours. In other words, it appears to us
that the existence of cooperative behaviours
and altruism in our social ethogram could
have a long evolutionary history. But, again,
an important question is: “Does true altruism
really exist?”
e study of altruism in animals is a very
interesting area of study, from an evolutionary point
of view. It is a powerful tool in understanding the
origin of part of human behaviour. Cooperation
and reciprocal altruism, for example, are essential
part of humans’ behaviour, and their origins can
be tracked down in other animals, with a special
JASs forum: Ethics, Altruism and Evolution
emphasis on non-human primates. Such approach
is in accord with an evolutionary framework,
characterised by a continuity of forms and
behaviour between humans and other animals.
However, a word of caution should be said about
the infl uence of the researcher’s personal point
of view in interpreting data regarding inherently
cooperative or non-cooperative nature of human
behaviour (and this goes also for who’s writing here).
Finally, we also think that the recognition
of common aspects of altruistic behaviour
between human and non-human animals
should not be taken as a shortcut to affi rm
the existence of behaviours guided by a sense
of morality among non-human animals.
de Waal F.M.B. 2006. Primates and philosophers.
Princeton University Press, Princeton
Hamilton W.D. 1964.  e genetical evolution of
social behaviour. J.  eor. Biol., 7:1-52.
Huxley T.H. 1894 (reprinted in 1989). e
evolution of morality. Princeton University
Press, Princeton.
Warneken F., Hare B., Melis A.P., Hanus D. and
Tomasello M. 2007. Spontaneous altruism by
chimpanzees and young children. PloS Biol.,
Wilson E.O. 1975. Sociobiology: the new
synthesis. Cambridge, MA: University Press,
Socioecological influences on neurobiological domains are further analyzed. In addition to species-specific sets of behavioral profiles and social interactions, population growth represents a source for dynamic developments in social structure and individual fate. Brain neurogenesis and neural circuit ensemble formation undergo developmental stages that depend on brain complexity and socioecological (habitat) conditions of the considered species and brain regions. Neurobiological substrates associated with differences in social behaviors are considered. The concepts of motivation and altruism are analyzed. It is noted that among social behavioral profiles, neural circuits activated by “altruistic” behavior are superimposed to circuits involved in the mental processing of situations associated with the pleasure reward that follows action.
Full-text available
People often act on behalf of others. They do so without immediate personal gain, at cost to themselves, and even toward unfamiliar individuals. Many researchers have claimed that such altruism emanates from a species-unique psychology not found in humans' closest living evolutionary relatives, such as the chimpanzee. In favor of this view, the few experimental studies on altruism in chimpanzees have produced mostly negative results. In contrast, we report experimental evidence that chimpanzees perform basic forms of helping in the absence of rewards spontaneously and repeatedly toward humans and conspecifics. In two comparative studies, semi-free ranging chimpanzees helped an unfamiliar human to the same degree as did human infants, irrespective of being rewarded (experiment 1) or whether the helping was costly (experiment 2). In a third study, chimpanzees helped an unrelated conspecific gain access to food in a novel situation that required subjects to use a newly acquired skill on behalf of another individual. These results indicate that chimpanzees share crucial aspects of altruism with humans, suggesting that the roots of human altruism may go deeper than previous experimental evidence suggested.
A genetical mathematical model is described which allows for interactions between relatives on one another's fitness. Making use of Wright's Coefficient of Relationship as the measure of the proportion of replica genes in a relative, a quantity is found which incorporates the maximizing property of Darwinian fitness. This quantity is named “inclusive fitness”. Species following the model should tend to evolve behaviour such that each organism appears to be attempting to maximize its inclusive fitness. This implies a limited restraint on selfish competitive behaviour and possibility of limited self-sacrifices. Special cases of the model are used to show (a) that selection in the social situations newly covered tends to be slower than classical selection, (b) how in populations of rather non-dispersive organisms the model may apply to genes affecting dispersion, and (c) how it may apply approximately to competition between relatives, for example, within sibships. Some artificialities of the model are discussed.
Primates and philosophers Th e genetical evolution of social behaviour
  • F M B De Waal
  • W D Hamilton
de Waal F.M.B. 2006. Primates and philosophers. Princeton University Press, Princeton Hamilton W.D. 1964. Th e genetical evolution of social behaviour. J. Th eor. Biol., 7:1-52.
Th e evolution of morality
  • T H Huxley
Huxley T.H. 1894 (reprinted in 1989). Th e evolution of morality. Princeton University Press, Princeton.
Th e genetical evolution of social behaviour
  • F M B De Waal
de Waal F.M.B. 2006. Primates and philosophers. Princeton University Press, Princeton Hamilton W.D. 1964. Th e genetical evolution of social behaviour. J. Th eor. Biol., 7:1-52.