Hierarchical social structures are a widespread phenomenon in species ranging from anemones to humans and yet the behavioral processes that produce them remain poorly understood. This comprehensive study of dominance relationships will use crayfish to explore how animals modify their behavior in the context of aggressive interactions. This work will first characterize how previous fighting success modifies an organism's subsequent behavior in paired encounters. Since it is not intuitively obvious how relationships between such pairs develop into a complex social web in larger groups of animals, computer simulations of 'virtual' crayfish will explore more complex social structures. Predictions arising from these models will then be tested using real crayfish.
Results from this project should provide considerable insight into the complex associations that exist between different levels of organization, including sensory processes, dispositions for aggression, dominance status, and brain chemistry. Given the theoretical significance, evolutionary importance, and broad taxonomic spread of aggression, elucidating the mechanisms of formation and maintenance of dominance in these 'lower' animals will lead to a better understanding of the laws which govern social behavior. Results from this research may also have implications for the development of pharmaceuticals for the control of affective states, and for psychologists investigating the role of past experience in aggressive behavior.
