Clinical psychology uses the understandings derived from developmental and abnormal psychology to diagnose and treat mental disorders and adjustment problems. 

Comparative psychology explores the differences and similarities in the behaviour of animals of different species. 
Developmental psychology studies the emotional, intellectual, and social changes that occur across the life span of human beings.
Industrial psychology is concerned with people at work. Industrial psychologists investigate such matters as how to make jobs more rewarding or how to improve workers' performance.

Social psychology studies the social behaviour of individuals and groups, with special emphasis on how behaviour is affected by the presence or influence of other people.