Hand-clasp Grooming

Hand-clasp grooming is a unique grooming posture in which two individuals sit facing one another, simultaneously raise one arm overhead, and support the other by holding hands or wrists to create an “A-frame” posture. Hand-clasp grooming is common in some, but not all wild chimpanzee communities, and since 1991, has been observed in one of the Yerkes groups.

Researchers are currenty examining over 15 years of continuous data in order to provide a more detailed description of handclasp grooming at Yerkes, determine if social affiliations have affected its spread, and to compare specific aspects of posture among the Yerkes chimpanzees to reports from wild populations.

Selected References

Bonnie, K. E. & de Waal, F. B. M. (2006). Affiliation promotes the transmission of a social custom: Handclasp grooming among captive chimpanzees. Primates, 47, 27-34. doi:10.1007/s10329-005-0141-0
Whiten, A., Goodall, J., McGew, W. C., Nishida, T., Reynolds, V., Sugiyama, Y., Tutin, C. E. G., Wrangham, R. W., & Boesch, C. (1999). Cultures in chimpanzees. Nature, 399, 682-685. doi:10.1038/21415