Professor Bodamer, Colleagues Publish Findings on Chimpanzees

'A Clear-cut Example of Cultural Traditions'

Gonzaga News Service 

SPOKANE, Wash. — Research published last month (Aug. 29) by Gonzaga University psychology Professor Mark Bodamer and four collaborating international scientists has revealed that chimpanzees are not only capable of learning from one another, but also use this social information to form and maintain local traditions.

The research shows that the ways chimpanzees groom each other depends on the community to which they belong. Specifically, it is the unique handclasp grooming behavior that reveals this local difference. The study, titled "Neighbouring Chimpanzee Communities Show Different Preferences in Social Grooming Behaviour" is reported in the journal Proceedings of the Royal Society B.

"It's a clear-cut example of cultural traditions," Bodamer said. "What we found is variation in that behavior in terms of the actual hand-clasping. These chimpanzees handclasp quite often and, thanks to the efforts of many, we have a very large data set of photos, video and field notes. Many examples were recorded by Gonzaga undergraduate students who took part in this study. The students also collected other behavioral observation data as part of the Gonzaga in Chimfunshi summer program."

Bodamer's co-researchers include Katherine A. Cronin, Edwin J.C. van Leeuwen, and Daniel B.M. Haun from the Max Planck Institute for Psycholinguistics, Nijmegen, The Netherlands; and Roger Mundry, from the Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.

The research took place at the 24,000-acre Chimfunshi Wildlife Orphanage Trust in Zambia through the Gonzaga in Chimfunshi program, and is part of Gonzaga's Study in Zambia initiative, which includes the Gonzaga in Zambezi Intercultural Servant Leadership Program and the Gonzaga in Monze Teacher Education program. In Zambia, Gonzaga students explore academically and socially relevant topics, in context, and take direct action to address economic, environmental and educational challenges.

Handclasp Grooming

The specific behavior the researchers focused on was the "grooming handclasp," in which two chimpanzees clasp onto each other's arms, raise those arms up in the air, and groom each other with their free arm. While this behavior has been documented before, the question remained regarding whether chimpanzees are instinctively inclined to engage in grooming handclasp behavior or if they learned this behavior from each other and pass it on to subsequent generations.

Van Leeuwen and Cronin conducted their observations between 2007 and 2012 at Chimfunshi together with a team of Gonzaga undergraduate students led by Associate Professor Bodamer. At Chimfunshi, a mix of wild- and captive-born chimpanzees lives in Miombo forest in the largest chimpanzee enclosures in the world. To collect and comprehend the detailed chimpanzee data, the researchers collaborated with a team of local chimpanzee caretakers who collected additional video data.

Cultural Significance

Previous research suggested the grooming handclasp might be a cultural phenomenon, just as humans across cultures engage in various greeting behaviors. However, these suggestions were primarily based on observations that some chimpanzee communities handclasp and others don't — not whether there are differences between communities that engage in the handclasp behavior.

Further, the early observation that only some groups engage in the handclasp behavior could be explained by differences in genetic or ecological factors (or both) between the chimpanzee communities, which precluded the interpretation that the chimpanzees were exhibiting "cultural" differences.

Different Styles of Handclasping

This new study contributes significantly to research by showing that subtle-yet-stable differences exist between chimpanzee communities that engage in the grooming handclasp with respect to the styles of grooming they prefer. For example, one chimpanzee group much preferred the style in which they would grasp each other's hands during grooming; another group engaged much more in a style characterized by the folding of their wrists around each other's wrists.

"We don't know what mechanisms account for these differences," van Leeuwen said. "But we do know that these chimpanzee communities formed and maintained their own local grooming traditions over the last five years. In conjunction with observations in other species, it appears that humans are not the only species with social traditions. Our observations may also indicate that chimpanzees can overcome their innate predispositions, potentially allowing them to manipulate their environment based on social constructs rather than on mere instincts."

In addition to the different style preferences of the chimpanzee communities, the research team also observed that the grooming handclasp behavior was a long-lasting part of the chimpanzees' behavioral repertoire: the behavior was even transmitted to the next generation of potential hand-claspers.

Young Chimpanzees Learn Local Traditions

"By following the chimpanzees over time, we were able to show that 20 young chimpanzees gradually developed the handclasp behavior over the course of the five-year study," Bodamer said. "The first handclasps by young individuals were in partnership with their mothers. These observations support the conclusion that these chimpanzees socially learn their local tradition, and that this might be evidence of social culture."

Continued monitoring of these groups of chimpanzees will shed light on the question of how these group traditions are maintained over time and potentially even why the chimpanzees like to raise their arms up in the air during grooming in the first place, van Leeuwen added.

'Incredible Third World Liberal Arts Opportunity'

Bodamer sees Chimfunshi as "an incredible Third World liberal arts opportunity," and has taken other faculty colleagues there as well. Most recently, faculty colleagues and students from Gonzaga's biology department, School of Engineering and Applied Science and its Master of Arts in teaching English-as-a-Second Language (MA-TESL) program were on site this summer.

"The engineering students were bringing several Senior Capstone projects to fruition. These projects were designed to improve the lives of the people or the chimpanzees. Students worked with Engineering faculty (Alex Maxwell), and with Professor Bodamer. Travel to Chimfunshi gave researchers the opportunity to bring their ideas to life. MA-TESL students and (Associate Professor) Director Mary Jeannot taught the staff wives English," Bodamer said. "My students observed and recorded the chimpanzees' behavior and did some other observational research. The Gonzaga biology students did some chimp observation, but their goal was to experience the biological diversity of Chimfunshi in as many ways as possible; therefore, they went on bush-walks daily. Among the many special moments, each night we gathered around the campfire and everyone shared personal reflections on what they have discerned through their experiences."

Bodamer, a psychologist who finds the study of animal behavior fascinating, has taken contingents of Gonzaga students, faculty and even some interested and qualified Gonzaga community members to Zambia each summer for the past five years in two, four-week sessions. (Professor Bodamer started this program at Pacific University and has been traveling to Chimfunshi — and sharing its wonders with others — since 2002.)

"This coming summer I hope to have other faculty members involved, including faculty from new areas such as philosophy and religious studies," said Bodamer, who views Chimfunshi as a "Third World liberal arts field station" where students can experience hands-on research in multiple disciplines, including educational outreach to local children and adults. Service work at the site is important to Bodamer as well. In 2007, Bodamer and colleagues constructed an elementary school for staff children so they would not have to walk 20 kilometers to the nearest school — living out Gonzaga's Catholic and Jesuit mission that calls for loving service to others, particularly the poor and marginalized.