The field of psychology is a collection of diverse subfields. psychologists who conduct research contribute by expanding the knowledge base of psychology, whereas others who conduct research explore practical problems.- behavior genetics; behavioral- neuroscience; evolutionary- counseling; clinical- basic; applied

basic;applied                    

Explanation:

Basic research- This is a systematic study administered toward understanding and greater knowledge of the basic aspects of event and observable facts without particular applications towards products and processes in mind. It expands our wisdom and leads to innovation.

Applied research- This is a methodology used to solve a practical, and specific problem of a group or an individual. This research is used in medicine, business, and education to find various solutions for the same.

the answer to your question is,

old stone age.

-mabel < 3