The reviewer takes issue with Powers claim of no innate
chimpanzee aggression and territoriality but is sympathetic
to the the idea ecological consequences (crowding,
deforestation, artificial provisioning) have on the genetic
behavior of the chimpanzee. I would extrapolate this
somewhat and ask what effects deforestation and crowding
have on the genetic behavior of human communities. IMO
certainly both humans and chimpanzees have innate aggression
and territoriality and apparently it can viciously express
itself in the absence of obvious ecological pressures.
Still, it would seem likely such ecological pressures could
help trigger and exacerbate such innate aggression and
territoriality.
Michael Ragland
Original reference: Moore, J. (1992). The Egalitarians -
Human and Chimpanzee (book review). Am. J. Phys. Anthropol.
88: 259-262.
THE EGALITARIANS--HUMAN AND CHIMPANZEE. By Margaret Power.
Cambridge: Cambridge University Press. 1991. 290 pp. ISBN 0-
521-40016-3
As researchers searched for the fundamental nature of
primate behavior [sic] in the 1960s, grey langurs were seen
as a peaceful alternative to hierarchical and aggressive
baboons. They rarely fought and dominance was relatively
unimportant; infant-care was shared in this cooperative
society. There were some reports of fighting and even
infanticide by Japanese and Indian primatologists, but there
was no plausible theoretical model available to "explain"
such observations. The reports languished until the mid
1970s, when they were set into theoretical
suddenly infant-killing langurs were paradigmatic exemplars
of the selfishness of natural selection (e.g., Vogel, 1979).
A number of researchers did not accept this revision of
langur nature, and argued forcefully that the observed
violence was the result of crowding induced by humans via
either deforestation or artificial provisioning (Boggess,
1984). They pointed to the locally high densities at some
provisioned sites, and noted that under such circumstances
conflicts could not be resolved by simple avoidance and
group fission; violence begat violence and vulnerable
infants died. This view was not based in any ultimate
theoretical model but instead emphasized ontogenetic and
social structural factors. The "behavioral pathology"
explanation for male takeovers and infanticide in langurs
has been abandoned by most people in light of further data
from sites where langurs are not fed--but not before forcing
researchers to examine carefully the ecological bases of the
very real differences in social behavior and structure that
had been observed, differences that tended
Chimpanzee behavior is deja vue all over again. Initial
descriptions of non-hierarchical and unagressive apes living
in open, fission-fusion groups that met occasionally for
"carnivals" of display and grooming were hailed as evidence
of innate human goodness; Suzuki's observation of
cannibalism at Budongo in 1967 seemed an easily ignored
aberation. Then in the mid-1970s "war" broke out among the
chimpanzees studied by Jane Goodall and others at Gombe
National Park. Males of one community seemed systematically
to annihilate a neighboring group, and infanticide and
cannibalism were observed repeatedly, both within and
between communities. Similar events soon were observed by
Toshisada Nishida and colleagues at Mahale National Park,
the only other multi-decade chimpanzee study site (both are
in Tanzania, about 150 km apart). These observations fit
neatly into an emerging model of chimpanzee society as male-
bonded and territorial, and our cousins were transformed
from "the merry pranksters of the primate world" into
"killers, soldiers, organized warriors" (Ghiglieri, 1987).
Organized warfare, not carefree carnival, shapes chimpanzee
sociality. As our closest relative, this new chimpanzee
provokes some to ask, "Does war run in our genes like
baldness and diabetes?" (Ghiglieri, 1987).
Now Power challenges the revision, arguing that chimpanzees
are indeed the peaceful, open, jolly creatures of early
reports, when not driven to warfare and cannibalism by human
provisioning as at Gombe and Mahale. This tempts the
reviewer in two directions: first, to analyze her argument's
technical merits, and second, to discuss the form of both
controversies (make it three; see Ferguson, 1992) with
reference to Hobbes and Rousseau and the search for Human
Nature. As a primatologist rather than philosopher/historian
I focus on the first, but make no mistake--the second holds
the key to a deep understanding of the book. (A prediction:
sometime in the next decade bottlenose dolphin will be seen
doing something really nasty, and others will blame it on
stress induced by the noise of the observer's boat.) [1998
Eprint note: Infanticide has just been reported for one
dolphin population by Patterson et al. 1998; we shall see if
the rest of this prediction comes true.]
There are three intertwined elements to the book. The
central idea is based on Woodburn's description of "immediate-
return foraging systems" among gatherer-hunters; with
minimal property and no formal legal, religious, political
or economic institutions, "The totality of necessarily
positive social relations between all members of the immediate-
return societies constitutes the social structure" (p. 41,
original emphasis). Such societies are necessarily
egalitarian and disputes resolved by temporary fission;
according to Power, this view of gatherer-hunters (which she
develops based almost entirely upon the work of Woodburn and
Turnbull) applies equally well to chimpanzees. Thus, both
chimpanzees and humans, when living in their "natural
state," are peaceful egalitarians--provided that contrary
data can be explained away. The book is most interesting
when she attempts to integrate her views of chimpanzees and
gatherer-hunters with psychological literature and deWaal's
studies of captive chimpanzees to explore the implications
of immediate-return foraging for what she calls a "mutual
dependence system," based on the interaction of
"charismatic" and "dependent" social roles.
The bulk of the book is spent arguing that post-provisioning
data gathered at Gombe and Mahale describe stressed animals
and do not reflect normative patterns. To understand
chimpanzees, only early Gombe and Mahale data (prior to 1965
& 1968, respectively), or data from "naturalistic" research,
is reliable; she draws primarily on the work of Reynolds,
Kortlandt & colleagues, Sugiyama, and Ghiglieri. The last
portion of the book attempts to develop a theoretical model
explaining why chimpanzee society goes wrong the way it does
when faced with ecological stress, and speculates about
possible "genetic factors" underlying her proposed mutual
dependence system in humans, apes, humpback dolphins and
perhaps mammals in general.
Power's thesis is that while provisioning itself is not so
bad (just another heavily-fruiting tree in the eyes of a
chimpanzee), artificially limiting access to food by
enclosing bananas in boxes (Gombe) or dispensing sugarcane
one piece at a time (Mahale) is intensely frustrating for
animals forced to wait upon the whim of some human for a
bite to eat. Frustration leads to aggression; as aggression
becomes a way of life near the provisioning site,
individuals lose the social skills needed to interact
peacefully with relative strangers and so normal dispersal
by both males and females is inhibited (some female
swellings). Hostile communities are created and warfare
between them is born.
The speed and repeatability with which these events unfold
suggest a "natural" basis. Power argues that while
egalitarian societies are favored when there is enough to go
around, total egalitarianism in the face of severe famine
might result in the death of all. Propensities toward
aggression, hierarchy, cannibalism, communities and
intercommunity conflict have evolved as latent safeguards;
basically, when ecological disaster strikes, they kick in to
break up affiliative social bonds and make life awful enough
that a few individuals will disperse from their otherwise
too-pleasant society into some empty habitat, thus ensuring
survival of the species.
Power makes a strong and interesting case for the possible
significance of frustration in shaping chimpanzee behavior
at Gombe and Mahale. Her ideas deserve serious consideration
by behavioral ecologists; we too often skip over the
psychological processes that serve to translate genes into
behavior, and to ignore completely the possibility that such
processes might be affected in systematic and perhaps non-
adaptive ways. Her argument, however, is seriously flawed in
three general ways.
First, there is the group selection rationalization of
chimpanzees' latent aggressiveness (e.g., "The ultimate goal
of the entire set [of genetic attributes] is survival of the
species," p. 239). Closely coupled to this is a view of a
"natural," "vanished uncrowded world" in which rather than
kill the neighbors, subgroups might undertake an "arduous
journey" to some suitable habitat heretofore unoccupied by
chimpanzees. Neither her units of selection nor the arena in
which selection occurs is consistent with general
evolutionary or ecological thought. This is not fatal to her
criticism of the 'aggressive chimpanzee' story; she simply
fails to replace it with a convincing explanation of her own
(too bad; she proposes a genetic basis for TGIF parties [p.
252-3] that I found quite appealing).
Second, her scholarship is poor, partly a matter of
carelessness and partly because all reports are accepted at
face value. It is vital that any reader unfamiliar with the
chimpanzee literature realize this--her assertions cannot be
relied upon. For example: "Similarly, there was no
territoriality in the sense of exclusive use of space among
the Mahale apes in the early years (Azuma and Toyoshima
1962)" (p. 70). Azuma & Toyoshima in fact worked at Kabogo
Point, an ecologically distinct site about 75 km from
Mahale; though they do state that "groups" are non-
antagonistic and non- territorial, it is clear that their
"groups" are equivalent to temporary parties ("The size of a
group ... varies from 2 to 3 heads to 20 to 30 heads" (Azuma
& Toyoshima, 1962: 63), and furthermore they did not
recognize individuals (p. 68). Minimal interpretation on
Power's part would have indicated that these data do not
demonstrate non-territoriality at Kabogo, let alone Mahale.
Similarly, when arguing that predominantly male-inititated
copulation is another consequence of provisioning (p. 78),
she states that Albrecht & Dunnett (1971) "point out that
only about one-quarter of the copulations in their
(categorically wild) group in Guinea were initiated by
males. [Unfortunately no numbers are given]." While they do
make this point, they also note that their sample is
"insufficient" and elsewhere indicate that "about 10"
copulations were observed at Kanka Sili, the site in
question (Albrecht & Dunnett, p. 39). Power either missed
this or does not recognize the (in)significance of such a
small sample. See also her site map's innacurracies (p. 22),
blending of Budongo and Mahale (p. 97), and use of Albrecht
& Dunnett's failure to see a predation during 3 months of
observation in a plantation clearing as evidence that
leopards are not serious threats to chimpanzees (p. 60). The
nature of her hypothesis forces her to use the sparse data
obtained by studies of unhabituated apes, but to use it so
uncritically renders her book provocative but without
substance.
The third flaw is her failure to discuss pertinent
observations from Mt. Assirik or even to mention the Tai
forest, both sites of longterm research on unprovisioned
apes living in far more pristine habitats than several she
classes as having "wild" (i.e., normal) chimpanzees. The Mt.
Assirik community conducted a series of violent nightime
attacks on a group of chimpanzees being rehabilitated near
there, forcing the rehabilitation program to close (Goodall,
1986: 521) and the death of an adult male in the community
was attributed to attacks by other chimpanzees (Baldwin,
1979: 69-71). Intercommunity relationships among the Tai
chimpanzees have not been explicitly reported upon, but
Boesch & Boesch (1989: 567) discuss the possible impact of
"territorial fights" (29 seen in 29 months) on male grouping
patterns there; carnivals and open networks seem ruled out.
I could understand an attempt to explain away these reports,
but to ignore them totally is either massive oversight (a
book emphasizing the importance of research on unprovisioned
chimpanzees overlooking the two longest qualifying
studies?), or a deliberate stacking of the evidence.
However, her thesis cannot be dismissed as readily as her
handling of the evidence with which she supports it. Despite
its faults, it is founded on a true and troubling statement:
"Despite more than 30 years of study ... there is no firm
agreement as to the social organization of [chimpanzees]"
(p. 1). Anyone believing this to be hyperbole should see,
for example, Rodman's recent attempt to force Mahale
chimpanzees into a Gombe mold (Rodman, 1991). Coming back to
langurs (unimale at some sites, multimale at others), my own
feeling is that this is because there is no such thing as
the social organization of chimpanzees. Pace Rodman,
Wrangham's model probably does not apply to all chimpanzee
populations. It is difficult to see how it could work when
home ranges surpass 200 km2 and densities fall below
0.01/km2, and Mahale/Gombe differences appear real, though
subtle. Territorial conflict and closed communities at Gombe
and Mahale do not preclude carnivals and open social
networks at other sites, and vice versa. We need a better
idea of precisely how ecological factors, acting through
demographic variables, determine the behavioral options open
to chimpanzees at different sites. Until we have such
understanding it would be premature to reject the theses
that (1) aggressive territoriality is not "normal" among
some [all?] chimpanzee populations, and (2) "artificial"
frustration may have played a significant role in
structuring the intercommunity violence seen at Gombe and
Mahale (though this is long odds indeed).
The Egalitarians does not live up to its forward (by Ashley
Montagu; probably the most effusive ever penned), but it
does set out an interesting hypothesis and remind us of some
puzzling observations. Hopefully chimpanzee researchers and
historians of science will find it stimulating. Others
should probably ignore it, or proceed with extreme caution.
JIM MOORE
Anthropology Department University of California, San Diego
La Jolla CA 92093 LITERATURE CITED Albrecht, H. & Dunnett,
S. C. (1971). Chimpanzees in Western Africa. Munich: R.
Piper & Co. Azuma, S. & Toyoshima, A. (1962). Progress
report of the survey of chimpanzees in their natural
habitat, Kabogo Point area, Tanganyika. Primates. 3: 61-70.
Baldwin, P. J. (1979). The natural history of the chimpanzee
(Pan troglodytes verus) at Mt. Assirik, Senegal. PhD thesis,
University of Stirling. Boesch, C. & Boesch, H. (1989).
Hunting behavior of wild chimpanzees in the Tai National
Park. Am. J. Phys. Anthrop. 78: 547-573. Boggess, J. (1984).
Infant killing and male reproductive strategies in langurs
(Presbytis entellus). pp. 283-310 IN Hausfater, G. & Hrdy,
S. B. (Eds.), Infanticide: Comparative and Evolutionary
Perspectives. New York: Aldine. Ferguson, R. B. (1992).
Tribal Warfare. Sci. Amer. 266: 108-113. Ghiglieri, M.
(1987). War among the chimps. Discover. 8: 66-76. Goodall,
J. (1986). The Chimpanzees of Gombe: Patterns of Behavior.
Cambridge: Harvard University Press. Rodman, P. S. (1991).
Book review of The Chimpanzees of the Mahale Mountains. Int.
J. Primatol. 12: 629-632. Vogel, C. (1979). Der Hanuman-
langur (Presbytis entellus), ein Parade-Exempel fur die
theoretischen Konzepte der "Soziobiologie"? pp. 73- 89 IN
Rathmayer, W. (Ed.), Verhandlungen der Deutschen
Zoologischen Gesellschaft 1979 in Regensburg. Stuttgart:
Gustav Fischer Verlag.
------------------------------------
Patterson, I. A. P., Reid, R. J., Wilson, B., Grellier, K.,
Ross, H. M. & Thompson, P. M. (1998). Evidence for
infanticide in bottlenose dolphins: An explanation for
violent interactions with harbour porpoises? Proc. R. Soc.
Lond. B. 265: 1167-1170.
"It's uncertain whether intelligence has any long term
survival value." Stephen Hawking