Colloquially, personality has been defined as "the totality of an individual's behavioral and emotional tendencies" (Woolf et al., 1977). A scientific approach to personality, in contrast, requires a working definition that suggests falsifiable hypotheses. Research on personality and health across the life course has conceived of personality as an organizing structure made up of constituent attitudes, patterns of behavior, cognitions, emotions, and other basic psychological processes, all of which have implications for how people affect and are affected by the social and physical environments.