Since the 1950's psychological research has attempted to define adaptive behavior, i.e., competence. To develop a system for explaining effective behavior, an international team of researchers developed a conceptualization of competent behavior which included three components: coping behaviors, motivation, and attitudes. A set of internationally usable, reliable measures was developed and compared to objective criteria of school achievement for 14-year old children (N=5400) from 8 countries. The coping/motivation measures showed substantial power to predict and explain achievement, both alone and in conjunction with aptitude, e.g., as high as 56% of the variance in one country. Results indicated that national samples and cohorts differed on the kinds of coping skills affected by achievement. Defensive behavior proved adverse to good achievement in all countries except Japan. In addition, strength of motivation, estimated by aspiration scores, was a powerful predictor of achievement. The findings suggest that more research is needed in the construction of a general theory of effective behavior. (Author/KMF)