-At the same time, subspecies differences in social instincts also made them particularly _frustrating_, as friendships. Particular squirrels had a subspace of their behavior that characterized them as different from other individuals of the same age and sex: _personality_ being the technical term (coined in Dunbar's volume on social systems). The friendship-forming instinct was most stimulated between squirrels with similar or at least compatible personalities, and the two subspecies had different personality distributions that resulted in frequent incompatibilities: for example, west-valley ground squirrels tended to have a more anxious disposition (reflecting the need to be alert to predators on open terrain), whereas east-valley tree squirrels tended to have a more rambunctious nature (as was useful for ritual leaf fights, but which tended to put west-valley ground squirrels on edge).
+Particular squirrels had a subspace of their behavior that characterized them as different from other individuals of the same age and sex: _personality_ being the technical term (coined in Dunbar's volume on social systems). The friendship-forming instinct was most stimulated between squirrels with similar personalities, and the two subspecies had different personality distributions that resulted in frequent incompatibilities: for example, west-valley ground squirrels tended to have a more anxious disposition (reflecting the need to be alert to predators on open terrain), whereas east-valley tree squirrels tended to have a more rambunctious nature (as was useful for ritual leaf fights, but which tended to put west-valley ground squirrels on edge).