@article{oai:ir.soken.ac.jp:00003509,
 author = {沓掛, 展之 and KUTSUKAKE, Nobuyuki},
 issue = {8-9},
 journal = {Behaviour, Behaviour},
 month = {Aug},
 note = {Current theory on primate social relationships implies that relationship quality consists of three factors: value, security, and compatibility. The relationship security of each group member can be determined using the level of social anxiety found when that individual is in the proximity of other individuals. I studied social anxiety by measuring the rate of rough self-scratching behaviour (RSS), a self-directed behaviour, in wild chimpanzees in Mahale Mountains National Park, Tanzania. The RSS rate drastically differed across individual activities; RSS was rare when the focal individual was foraging or moving, but frequent during resting. The male RSS rate while resting was inversely correlated with dominance rank, particularly when males were with other group members; higher-ranking males performed RSS less often than lower-ranking males. The RSS frequency of males did not vary with the proximity of group members or the association level of the individuals in proximity. In contrast, close proximity of group members increased the female RSS rate. In addition, females performed RSS more frequently when a non-affiliative group member was in their proximity than with an affiliative group member. The relative dominance rank of the individuals in close proximity did not affect the RSS rate in either males or females. Furthermore, infant contact or separation from the mother did not influence the maternal RSS rate. These results suggest that anxiety-inducing situations differ between sexes in this species, and that for female chimpanzees, relationship security is related to association level. The results are discussed in terms of interspecific variation in social dominance style and inter-individual tolerance within primates.},
 pages = {1153--1171},
 title = {Assessing relationship quality and social anxiety among wild chimpanzees using self-directed behaviour},
 volume = {140},
 year = {2003}
}