Word Origin & History
short for psychology in various senses; as an academic study, in student slang by 1895. The verb is generally negative when used transitively, positive when intransitive; first attested (also psych out) 1934 as "to outsmart," from 1963 as "to unnerve." However to psych (oneself) up is from 1972; to be
psyched up is attested from 1968.