Introduction

"...Social grooming is the glue of primate life..."

(Dario Maestripie, Primate Psychology)

Figure 1: Hamadryas Baboons performing allogrooming (primatology.net)

Social Grooming in Primates

Grooming refers to behaviors involved in cleaning and maintaining body function and hygiene. 
 
Social grooming, or allogrooming, is grooming of one individual by another.  This behavior is displayed by many different animals, including mammals, insects, fish, and birds (Britannica.com).  Social grooming is widespread among primates, where it serves a primarily social purpose, rather than a hygienic one (Henzi and Barrett, 1999). 

Figures 2 & 3: Interactions in large group of primates (www.ippl.org); a rhesus monkey grooming another (www.grg.org)

Extensive studies have been conducted for the better understanding of the purpose behind this seemingly altruistic behavior, and our website will attempt to take a deeper look at the significance of the behavior from the biologist's perspective. 

Using Niko Tinbergen's "four questions" as a guide, we will discuss  the evolution of primates and emergence of the social function of the behavior (phylogeny), the development of the behavior during a individual's lifetime (ontogeny), the specific biological and chemical processes and motivations responsible for the behavior (mechanism), and how the behavior increase the fitness of individuals, allowing for its continual selection in primates (adaptive value).