A new study led by University of New Mexico alumni and faculty members reveals that mother chimpanzees prioritize play with their children even in difficult situations, like food scarcity.
The study, published March 14 in the journal “Current Biology,” might shed light on the importance of play to development in other primate species, and help us learn more about our evolution, according to lead researcher and UNM alumna Kris Sabbi.
Co-authors include UNM professors of anthropology Melissa Emery Thompson and Martin Muller, UNM anthropology graduate student Megan Cole and UNM alumna and University of Michigan Research Lab Coordinator Isabelle Monroe.
For chimpanzees who are not mothers, periods of food scarcity mean prioritizing themselves and conserving energy, Cole said. For mothers, it’s different.
“Mothers are having to prioritize the needs of their kids in addition to the needs of themselves,” Cole said.
This research helps challenge the notion that humans are the only species capable of play, as made canon by works like Johan Huizinga’s “Homo Ludens.” The fact that chimpanzees – which are genetically close to humans – also prioritize play may point to something in our shared evolutionary history, Sabbi said.
“We tend to be stuck in this way of thinking that human beings are the only creatures,” Sabbi said.
Mother chimpanzees will break away from the larger group to forage and hunt with their children, and often become their children’s sole playmates. This reveals to researchers how high of a priority engaging in play is to chimpanzees, according to the study.
“Based on these findings, it suggests that they are really considering the developmental needs of their kids, and that includes social development,” Cole said.
The new study is derived from the Kibale Chimpanzee Project, based in Uganda. Emery Thompson and Muller serve as directors of the project. Observations are gathered in Uganda by researchers and sent to be analyzed by research assistants based in institutions like UNM, Cole and Sabbi said.
The idea for the study followed an observation of a gradual increase in the number of adult chimps engaging in play during the summer of 2017, Sabbi said.
“When exploring archival data, it became clear that the highest periods of play were in May - June, which was also a period of high levels of food availability,” Sabbi said.
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The research challenges existing beliefs about adult play. In most species, the frequency of engaging in play drops off significantly after an animal’s development is complete. Previously, this was chalked up to play not being vital to adult animals. In reality, the reduced rates of play can probably be explained by animals having to cater to competing priorities in the wild, Sabbi said.
“They were less constrained by energetic availability or time spent eating and they could invest that into social things, like playing,” Cole said.
According to the study – which analyzed 4,000 bouts of play during periods of interest – play happened almost once a day. When food was abundant, adult female chimpanzees also played with each other rather than with their kids.
“Our prioritization of child-parent play may have developed as a result of the structure of our social systems,” Sabbi said.
Chimpanzees tend to have a rotating social group structure, where members of the group will separate from others for some periods of time before rejoining, Cole said. Throughout evolution, humans may have had more time for play as a result of the development of agriculture, Sabbi said.
Sabbi and Cole see applications for the findings in the field of psychology, especially in regard to child development, they said. Cole, in particular, is interested in studying the individual temperaments of chimpanzees and the correlation between a chimp’s personality and their physiology.
“It’s a question that leads to even more questions and that’s my favorite kind of science,” Sabbi said.
Shin Thant Hlaing is a freelance reporter at the Daily Lobo. She can be reached at news@dailylobo.com
