According to Osho, introversion and extroversion arise from accumulated impressions across countless lives and the habits we reinforce daily. Repeated outward pursuits—wealth, fame, lust—close the inner door; regular inwardness keeps it open. Society and education further condition us toward extroversion because it serves worldly success. Thus temperament is a momentum of karma and conditioning that can be reversed through conscious practice (silence, meditation).
You’re quiet or outgoing mostly because long-built habits (past lives + daily choices) and social training shape you—steady inner practice can change that.