Personality research: Components of variance attributable to the person and the situation.

Studies involving personality and situational variables were surveyed. Studies permitting determination of main effects and interactions involving these variables have increased since 1950. In one comparison, situational main effects were significant in 65.5% of the cases, whereas the figure was 31% for individual difference variables and 59.9% for interactions. In another comparison, 35% of situational main effects accounted for more than 10% of the variance, compared with 29% for personality indexes; 19% of the situational variable effects accounted for more than 20% of the variance, compared with 14% of the personality main effects. Low percentages of variance were accounted for by all variables investigated: situational, personality, demographic, and interactions among these variables.