In the baboon social network: 'Nice' gals may finish first

October 16, 2012

Some pairs of female baboons form relationships that look a lot like “friendships,” a group of researchers has found.

The females spend time hanging out together and grooming each other. They don’t fight so much and support each other when they get into conflicts with other members of their groups. These relationships seem to confer important benefits on females, including living longer, reproducing more successfully, and coping better with stress. Baboon females grooming Download Full Image

Arizona State University primatologist Joan Silk is one of a team of researchers, including Robert Seyfarth and Dorothy Cheney at the University of Pennsylvania, who have been documenting the social lives of female baboons in the Okavango Delta of Botswana.

“We have spent years monitoring the social lives of baboons and other primates, with the idea that evolution has shaped social behavior to enhance the reproductive success of individuals,” said Silk. “But we were not able to link what we knew about variation in social behavior to the reproductive success of individuals. Now we can. And this raises new questions that we wanted to go back to the data to answer.”

In particular, Silk and her colleagues wondered why some female baboons form these close social “friendships” and others do not, and why some female baboons were more successful than others at forming strong social bonds. Seyfarth, Silk, and Cheney’s paper on the “Variation in Personality and Fitness in Wild Female Baboons” was published in the October 1, 2012 in the Proceedings of the National Academy of Sciences.

The long-term study focused on detailed records of 45 wild female baboons observed in the Moremi Game Reserve in Botswana from 2001 to 2007.

Some explanation for the friendly behaviors were due to availability of close relatives – mothers, daughters, sisters – with whom females typically form very close bonds. Silk and her colleagues wondered if, using the observational data collected over the course of seven years, they could find out if the behavior of the females themselves corresponded to personality types.

The literature on personality in animals has two different histories. One comes from psychology where researchers look at personality dimensions that are seen in humans and also seen in animals, like extroversion or introversion. The other comes from behavioral ecology where researchers ask whether a personality characteristic is advantageous or disadvantageous, such as being shy or bold, to answer what does being shy or being bold get you living in the world? The researchers wished to find a middle ground between these two approaches and relied on the animals’ interactions to define their “personality styles.”

The researchers tabulated the frequency of various types of behavior, including friendly things like embraces and hostile things like threats and attacks. They also kept track of whether females grunted when they approached other females. Grunting signals an intention to behave nicely, and females use grunts to resolve conflicts, to reassure lower ranking females that they won’t harm them, and to facilitate interactions with mothers of newborn infants. (For reasons that we don’t fully understand, baboons are fascinated by other females’ babies and often try to smell, touch and handle them.)

This procedure generated three personality dimensions that the researchers labeled “Nice,” “Aloof,” and “Loner.” The Nice females were more likely to perform friendly behaviors. They were also more likely to grunt when they approached others and spent little of their time alone. Aloof females were more aggressive than others and grunted at high rates only when approaching higher-ranking females who had infants that they wanted to handle. Loner females were often alone and grunted most frequently only when approaching high-ranking females. These personality traits seemed to be relatively consistent from year to year. Females’ personality styles were related to the strength of their social bonds with other females – Nice females were more likely to have strong social bonds than other females. Thus, niceness may ultimately be linked to females’ longevity and reproductive success.

The analyses of behavioral traits were supplemented by testing the baboons for levels of cortisol, a hormone associated with stress. The Loner females had much higher levels of cortisol than the Nice or Aloof females.

Silk’s research centers on the evolutionary processes that shape behavior and examines the value of relationships to females. Her work suggests that there are important parallels between humans and other primates.

“We know that some people are more likely to form social bonds than others, and the quality of social networks has important effects on health and life span. Baboons seem to be much the same,” said Silk. “We are not yet sure how deep these similarities are, but it seems likely that these kinds of close, supportive, stable relationships have played an important role in the lives of humans for millions of years.”

Joan Silk is a professor in the School of Human Evolution and Social Change and an affiliated scientist with the Institute of Human Origins, which are both in the College of Liberal Arts and Sciences.

Julie Russ

Assistant director, Institute of Human Origins


Promise of stem cell research focus of Arizona Science Center talk

October 16, 2012

One of the next big leaps in biomedical science and engineering is likely to come when more secrets are revealed about the workings of stem cells.

New discoveries could enable repair of severe damage to the body through the abilities of stem cells to multiply and develop, says Karmella Haynes, an assistant professor in the School of Biological and Health Systems Engineering, one of the Ira A. Fulton Schools of Engineering at Arizona State University. Karmella Haynes Synthetic Biology Lab Download Full Image

Haynes, whose work focuses on synthetic biology, will talk about what advances in stem cell research promise for the future at 7 p.m., Nov. 2, at the Arizona Science Center.

“Most of us have observed how our bodies heal themselves from minor wounds, such as scrapes and cuts, by growing new skin. Some animals such as starfish, geckos and aquarium zebra fish can grow whole limbs and even vital organs by keeping a supply of stem cells on reserve throughout their lives,” Haynes explains.

“We may someday be able to use stem cells to repair, or even re-grow, lost organs or limbs for humans,” she says.

Before coming to ASU, Haynes spent three years conducting biological research at Harvard University. She earned a doctoral degree in molecular genetics at Washington University in St. Louis.

Her interest in genetics was sparked during a summer research internship at the Massachusetts Institute of Technology during her undergraduate years. That interest would later lead to a post-doctoral position in synthetic biology at Davidson College in North Carolina.

Among a range of research pursuits, Haynes’s work at ASU includes development of a synthetic protein that is able to control gene expression and slow the growth of cancer cells.

The Arizona Science Center is at 600 E. Washington Street in downtown Phoenix. Haynes will speak as part of activities during the center’s monthly Adults Night Out.  

Admission to Haynes’ talk is free, and audience members will have the opportunity to ask questions.

Joe Kullman

Science writer, Ira A. Fulton Schools of Engineering