It could be said that psychology looks at what is inside of the individual human mind, while sociology looks at the external and group mind of many individuals. Psychology students learn about the biological functions of the brain as they apply to behavior, personality, memory, intellect, perception and senses, and social behavior, among other factors. Sociology examines human interactions and behaviors with favor toward humans as they function in and because of the influences of society. Instead of focus on personality, memory and senses, the sociology student works on norms, values, symbols, and social influences.
In reality, neither science can be so closely and exactly defined or confined, since psychology is a direct descendant of the sister sciences of anthropology and sociology, since all three sciences descend from philosophy. Psychology has expanded into sub fields that are now their own fields, such as neuropsychology, which combines technology, medicine and psychology in ways that are completely outside of the realm of psychology. Sociology has so many sub fields, ranging from medical sociology to environmental sociology that a person can spend an entire lifetime going down one path of inquiry.
Anthropology and sociology students study psychology in order to be aware of the way that psychological issues impact human activity, social interaction, and behavior. Sociologists are intensely aware that individual psychological factors impact group and individual behavior and interaction, deviance, and behavior in times of chaos.
Psychologists are well aware that social structure, values, norms and references are important to the development as well as in the pathology of individuals, but also focus on controlled experiments, forms of individual behavior modification, various forms of learning, and testing of the mental and intellectual functions. Quantitative analysis, complex analytical tools, and the history of human psychology, psychopathology, and psychotherapy are studied. Where large populations are studied, it is generally in the form of aggregated data and test results from individuals.
Sociologists and psychologists both study group behavior and dynamics, with sociologists focusing on interpersonal dynamics with focus on people as societal entities, while psychologists focus on the individual behavioral dynamics as the combined functions of people as biological entities.
In practical applications, a psychologist might approach an individual or family crisis from the viewpoint of healing or treating a pathology in order to improve quality of life, then determine if the therapy or problem solving could be applied to more individuals who are suffering from the same causes. A sociologist might approach an individual or family crisis from the viewpoint of correcting the societal, legal, financial or other issues that are making life difficult, then going further to determine how such approaches can be developed into programs that can be applied to and benefit the much larger society.