The chapter is divided into two parts. In the first part two well-known experiments on human reasoning are presented and then the prominent psychological theories of reasoning (mental logic, mental models theory, domain-dependent theory and heuristics and biases approach) are introduced. The second part deals with the debate among analytic philosophers and cognitive psychologists concerning the implications that experimental findings on human reasoning have for the evaluation of human rationality, known as the rationality debate, focusing especially on ecological, evolutionary and dual processes theories of reasoning. In the conclusion, the most recent developments in this field of research are presented.
