This study undertook to develop an improved conceptual system for explaining effective behavior; to build reliable measures of the components of that behavior; to develop and apply the measures internationally; and to validate the measures and concepts against objective criteria of achievement. An eight-nation team defined three sets of components of effective behavior: a sequence of coping actions; feelings and attitudes that facilitate effectiveness; and the intensity and particular kinds of motives for performing effectively. These elements are attained separately, though interactively, in five areas of behavior: achievement, peer relations, authority relations, and managing anxiety and coping with aggression. Projective, self-report, and peer rating instruments were developed with semantically equivalent editions in English, German, Japanese, Brazilian Portuguese, Slovenian and Mexican Spanish; and were given to boys and girls, age 10 and 14, in Sao Paulo, London, Milano, Tokyo, Mexico City, Austin, Texas, Chicago, Illinois, Ljubljana, Hanover, Heidelberg and Koblenz, West Germany. The conceptual system was supported. Coping skills did significantly affect achievement; and skill in the other areas of behavior also affected achievement. Strength of motivation proved a powerful, universal predictor of achievement. The kinds of motives for working significantly predicted achievement, but idiosyncratically in each country. (Author/BW)