Can we interpret irrational behavior?

According to some theories of interpretation, it is difficult to explain and predict irrational behavior in intentional terms because irrational behavior does not support the ascription of intentional states with determinate content. In this paper I challenge this claim by offering a general diagnosis of those cases in which behavior, rational or not, resists interpretation. I argue that indeterminacy of ascription and paralysis of interpretation ensue when the interpreter lacks relevant information about the system to be interpreted and about the environment in which the system is embedded. Moreover, the heuristics of interpretation that guide the ascription of beliefs can be limited in scope. In the end I suggest that by giving up the idea of a necessary rationality constraint on the ascription of intentional states we can develop a new framework for a more psychologically realistic account of interpretation.