Colin Cooper's reader on individual differences is aimed at 2nd and 3rd year students of psychology and education taking courses in personality, individual differences, abilities, psychometrics. It brings together some fifty key papers on the most important issues in the theory of personality, abilities, mood and psychometrics. Each paper is prefaced by a short introduction orientating the reader to the key points developed in the paper and to the associated theoretical issues. Papers are included which reveal some of the debates, problems and issues in the field.