This chapter introduces some recent developments in the areas of human reasoning and decision making. Regarding decision making, the chapter focuses on decision-under-risk, using problems which are explicitly described in linguistic or symbolic terms. Human common-sense reasoning is far more sophisticated than any current artificial intelligence models can capture; yet people's performance on, for example, simple conditional inference, while perhaps explicable in probabilistic terms, is by no means effortless and noise-free. It may be that human reasoning and decision making function best in the context of highly adapted cognitive processes such as basic learning, deploying world knowledge, or perceptuomotor control. Indeed, what is striking about human cognition is the ability to handle, even to a limited extent, reasoning and decision making in novel, hypothetical, verbally stated scenarios, for which our past experience and evolutionary history may have provided us with only minimal preparation.