The Collaborative International Dictionary of English v.0.48:

introversive \introversive\ adj. (Psychol.)
   directed inward; marked by interest in oneself or concerned
   with inner feelings. Contrasted with extroversive.
   [Narrower terms: introvert, introverted, introvertive;
   introvertish, shut-in ]. Antonym: {ambiversive. Also See:
   unsociable.
   [WordNet 1.5]

WordNet (r) 3.0 (2006):

introversive
    adj 1: directed inward; marked by interest in yourself or
           concerned with inner feelings [syn: introversive,
           introvertive] [ant: ambiversive, extraversive,
           extroversive]