You should join if you're interested in any sort of personality type theory, e.g. the Myers Briggs. We will be focusing on Socionics, a more complex theory from Eastern Europe that builds on Jung's theory of Psychological Types.
Socionics not only explores a Jung's personality in full, using all eight functions, but it also looks into our values, strengths & weaknesses, as well how we perceive the world and our relationships with other people.