WORKLOAD DISTRIBUTION AND DIVISION OF LABOR IN COOPERATIVE SOCIETIES

Cooperative groups are ubiquitous in animals, as are the challenges of allocating labor to accomplish cooperative tasks, including territory defense, hunting, and brood care. Individual contributions can differ in two ways, both of which can influence fitness: group members can vary in overall helpfulness (workload) or they can specialize on different tasks (division of labor). In this review, we encourage ad-ditional, simultaneous study of both workload distribution and division of labor. Historically, workload distribution has been studied in the contexts of collective action and cooperative offspring care. Both areas of research aim to understand how shared benefits can emerge from individual contributions, but they remain poorly integrated. We argue that each of these literatures has strengths that could benefit the other, and we highlight potential areas of crosstalk. Next, we review the literature on division of labor in taxa other than the eusocial insects, discuss parallels and differences in division of labor between eusocial insects and other animals, and encourage more work on cooperative, noninsect taxa. Rigorous work on individual contributions to cooperative tasks will expand our understanding of the causes and consequences of individual variation and the evolutionary stability of social living.