There are Freudian and Jungian and Skinnerian organizations, but I don't belong to any of those. The American Psychological Association's Division 8 calls itself the Society for Personality and Social Psychology, and I belong to it, but it currently has little to do with personality theory. (Psychologists interested in personality theory are more likely to participate in APA's Division 10, Psychology of the Arts, or Division 26, History of Psychology.) A small group called the Personology Society, which is totally independent of APA, includes a number of psychologists who are very interested in personality theory. However, membership in that organization is by invitation only, and you need to have done a good deal of research and writing and publishing about personality before you get invited. There is, alas, no general-membership organization devoted to personality theory. If you want to start one, let me know.