social psychology vs psychology

social psychology and psychology both are nouns.

Word	Noun	Adjective	Verb	Adverb
social psychology	Yes	No	No	No
psychology	Yes	No	No	No

As nouns, psychology is a hypernym of social psychology; that is, psychology is a word with a broader meaning than social psychology:

social psychology: the branch of psychology that studies persons and their relationships with others and with groups and with society as a whole
psychology: the science of mental life

Other hypernyms of social psychology include psychological science.

social psychology (noun)	psychology (noun)
the branch of psychology that studies persons and their relationships with others and with groups and with society as a whole	the science of mental life