Natural selection and psychological mechanisms that determine personality

State the basic tenets of evolutionary personality psychology by describing the role of natural selection and the psychological mechanisms that are thought to determine personality. Explain how unpleasant and problematic human characteristics like anxiety could have evolved.
Discuss the rationale behind the twin-study method and adoption studies of genetic influence. Give the general findings regarding the contribution of genetic influences on personality. Discuss any problems associated with each of these methods of research.

Must be APA style for in-text citations and references. Need a minimum of 350 words.