A study investigated Finnish high school students' second language learning motivation, attitudes, self-concepts, inhibitions, and selected personality traits. The study attempted to learn more about the nature, content, and functions of the "affective filter" in foreign language learning. A variety of relationships between these factors were found, and a number of "filter" and "non-filter" learner types were distinguished. The study's design, results, and implications for language teaching and for future research efforts are discussed. A bibliography of over 60 references is included. (MSE)