The human mind is filled with evolved decision mechanisms designed to meet adaptively important goals. In this article we lay out a framework for studying those mechanisms from the perspective of evolutionary psychology, emphasizing the importance of multiple influences of the environment on shaping the decision strategies and their operation. These strategies often take the form of simple heuristics constructed from building blocks that draw on evolved capacities, all of which fit to particular information structures in the environment. We illustrate these ideas with two examples of heuristics used in important adaptive domains: deciding when to leave a resource patch, and predicting when a sequence of events will stop or continue.