Psychology is the study of our mind, our behaviors, thoughts and emotions. There are many different sub-branches within the field of psychology. Some of these sub-branches are: developmental psychology, cognitive psychology, abnormal psychology, clinical psychology and industrial & organizational psychology.
Social Science is simply defined as a branch of study that deals with certain aspects of our society such as economics, political science or anthropology.
Humans are inherently social beings. We naturally crave and need interactions and connections with one another. Because of this, it makes sense that the study of our minds and how we behave (psychology) is considered a social science. In studying our mental processes, we do not consider these findings in a vacuum. On the contrary, we also contemplate how social situations, interpersonal relationships and societal factors can potential impact everything that we do.   _{Your Comment}