How motives, skills, and values determine what people do.

According to general behavior theory, motives, probability of success (or skill), and incentive value are three independent organismic determinants of excitatory potential (or the impulse to act) that combine with situational opportunity to determine response strength or response probability. Much con- fusion has been introduced into human motivation theory by investigators 'failure to measure separately motive strength (from coding operant thought) and incentive value (from value attitude questionnaires) and by their misuse of the term motivation. Moti- vation properly refers to an aroused motive, but they have broadened it to mean excitatory potential, which is determined partly by the aroused motive and partly by probability of success, incentive value, and other variables. Research is reviewed that dem- onstrates the importance of motivation, incentive value, and probability of success, independently mea- sured, for predicting achievement performance and the frequency with which affiliation acts are per- formed. Both theory and experiment lead to the conclusions that motive strength, particularly in re- lation to the strength of other motives in the person, is the more important determinant of operant act frequency, that incentive value is the more important determinant of cognitively based choices, that motive strength and probability of success combine multi- plicatively to predict response strength or probability, and that all determinants, plus this last interaction, together account for over 75% of the variation in operants like affiliative act frequency. The remainder of the variation is readily attributable to environ- mental opportunities.