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http://www.nytimes.com/2004/04/13/science/13BABO.html

April 13, 2004
No Time for Bullies: Baboons Retool Their Culture
By NATALIE ANGIER
 
ometimes it takes the great Dustbuster of fate to clear the room of bullies 
and bad habits. Freak cyclones helped destroy Kublai Khan's brutal Mongolian 
empire, for example, while the Black Death of the 14th century capsized the 
medieval theocracy and gave the Renaissance a chance to shine.

Among a troop of savanna baboons in Kenya, a terrible outbreak of 
tuberculosis 20 years ago selectively killed off the biggest, nastiest and 
most despotic males, setting the stage for a social and behavioral 
transformation unlike any seen in this notoriously truculent primate.

In a study appearing today in the journal PloS Biology (online at 
www.plosbiology.org), researchers describe the drastic temperamental and 
tonal shift that occurred in a troop of 62 baboons when its most belligerent 
members vanished from the scene. The victims were all dominant adult males 
that had been strong and snarly enough to fight with a neighboring baboon 
troop over the spoils at a tourist lodge garbage dump, and were exposed there 
to meat tainted with bovine tuberculosis, which soon killed them. Left behind 
in the troop, designated the Forest Troop, were the 50 percent of males that 
had been too subordinate to try dump brawling, as well as all the females and 
their young. With that change in demographics came a cultural swing toward 
pacifism, a relaxing of the usually parlous baboon hierarchy, and a 
willingness to use affection and mutual grooming rather than threats, swipes 
and bites to foster a patriotic spirit.

Remarkably, the Forest Troop has maintained its genial style over two 
decades, even though the male survivors of the epidemic have since died or 
disappeared and been replaced by males from the outside. (As is the case for 
most primates, baboon females spend their lives in their natal home, while 
the males leave at puberty to seek their fortunes elsewhere.) The persistence 
of communal comity suggests that the resident baboons must somehow be 
instructing the immigrants in the unusual customs of the tribe.

"We don't yet understand the mechanism of transmittal," said Dr. Robert M. 
Sapolsky, a professor of biology and neurology at Stanford, "but the jerky 
new guys are obviously learning, `We don't do things like that around here.' 
" Dr. Sapolsky wrote the report with his colleague and wife, Dr. Lisa J. 
Share.

Dr. Sapolsky, who is renowned for his study of the physiology of stress, said 
that the Forest Troop baboons probably felt as good as they acted. Hormone 
samples from the monkeys showed far less evidence of stress in even the 
lowest-ranking individuals, when contrasted with baboons living in more 
rancorous societies.

The researchers were able to compare the behavior and physiology of the 
contemporary Forest Troop primates to two control groups: a similar-size 
baboon congregation living nearby, called the Talek Troop, and the Forest 
Troop itself from 1979 through 1982, the era that might be called Before 
Alpha Die-off, or B.A.D. 

"It's a really fine, thorough piece of work, with the sort of methodology and 
lucky data sets that you can only get from doing long-term field research," 
said Dr. Duane Quiatt, a primatologist at the University of Colorado at 
Denver and a co-author with Vernon Reynolds of the 1993 book "Primate 
Behaviour: Information, Social Knowledge and the Evolution of Culture."

The new work vividly demonstrates that, Putumayo records notwithstanding, 
humans hold no patent on multiculturalism. As a growing body of research 
indicates, many social animals learn from one another and cultivate regional 
variants in skills, conventions and fashions. Some chimpanzees crack open 
their nuts with a stone hammer on a stone anvil; others prefer wood hammers 
on wood anvils. The chimpanzees of the Tai forest rain-dance; those of the 
Gombe tickle themselves. Dr. Jane Goodall reported a fad in one chimpanzee 
group: a young female started wiggling her hands, and before long, every teen 
chimp was doing likewise.

But in the baboon study, the culture being conveyed is less a specific 
behavior or skill than a global code of conduct. "You can more accurately 
describe it as the social ethos of group," said Dr. Andrew Whiten, a 
professor of evolutionary and developmental psychology at the University of 
St. Andrews in Scotland who has studied chimpanzee culture. "It's an attitude 
that's being transmitted."

The report also offers real-world proof of a principle first demonstrated in 
captive populations of monkeys: that with the right upbringing, diplomacy is 
infectious. Dr. Frans B. M. de Waal, the director of the Living Links Center 
at the Yerkes National Primate Research Center of Emory University in 
Atlanta, has shown that if the normally pugilistic rhesus monkeys are reared 
with the more conciliatory stumptailed monkeys, the rhesus monkeys learn the 
value of tolerance, peacemaking and mutual hip-hugging.

Dr. de Waal, who wrote an essay to accompany the new baboon study, said in a 
telephone interview, "The good news for humans is that it looks like peaceful 
conditions, once established, can be maintained," he said.

"And if baboons can do it," he said, "why not us? The bad news is that you 
might have to first knock out all the most aggressive males to get there."

Jerkiness or worse certainly seems to be a job description for ordinary male 
baboons. The average young male, after wheedling his way into a new troop at 
around age 7, spends his prime years seeking to fang his way up the 
hierarchy; and once he's gained some status, he devotes many a leisure hour 
to whimsical displays of power at scant personal cost. He harasses and 
attacks females, which weigh half his hundred pounds and lack his thumb-thick 
canines, or he terrorizes the low-ranking males he knows cannot retaliate. 

Dr. Barbara Smuts, a primatologist at the University of Michigan who wrote 
the 1985 book "Sex and Friendship in Baboons," said that the females in the 
troop she studied received a serious bite from a male annually, maybe losing 
a strip of flesh or part of an ear in the process. As they age and lose their 
strength, however, males may calm down and adopt a new approach to group 
living, affiliating with females so devotedly that they keep their 
reproductive opportunities going even as their ranking in the male hierarchy 
plunges.

For their part, female baboons, which live up to 25 years . compared with the 
male's 18 . inherit their rank in the gynocracy from their mothers and so 
spend less time fighting for dominance. They do, however, readily battle 
females from outside the fold, for they, not the males, are the keepers of 
turf and dynasty.

The new-fashioned Forest Troop is no United Nations, or even the average frat 
house. Its citizens remain highly aggressive and argumentative, and the males 
still obsess over hierarchy. "We're talking about baboons here," said Dr. 
Sapolsky.

What most distinguishes this congregation from others is that the males 
resist taking out their bad moods on females and underlings. When a dominant 
male wants to pick a fight, he finds someone his own size and rank. As a 
result, a greater percentage of male-male conflicts in the Forest Troop occur 
between closely ranked individuals than is seen in the control populations, 
where the bullies seek easier pickings. Moreover, Forest Troop males of all 
ranks spend more time grooming and being groomed, and just generally huddling 
close to troop mates, than do their counterpart males in the study. 

Interestingly, the male faces in the Forest Troop may have changed over time, 
but the relative numbers have not. Ever since the tuberculosis epidemic 
killed half the adult males, the ratio has remained skewed, with twice as 
many females as males. Yet the researchers have demonstrated that the troop's 
sexual complexion alone cannot explain its character. Examining other troops 
with a similar preponderance of females, the Stanford scientists saw no 
evidence of the Forest Troop's relative amity.

Dr. Sapolsky has no idea how long the good times will last. "I confess I'm 
rooting for the troop to stay like this forever, but I worry about how 
vulnerable they may be," he said. "All it would take is two or three jerky 
adolescent males entering at the same time to tilt the balance and destroy 
the culture." 


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