WordNet (r) 3.0 (2006):

insensitivity
    n 1: the inability to respond to affective changes in your
         interpersonal environment [syn: insensitivity,
         insensitiveness] [ant: sensitiveness, sensitivity]

Moby Thesaurus II by Grady Ward, 1.0:

100 Moby Thesaurus words for "insensitivity":
   Philistinism, analgesia, anesthesia, armor, bad manners,
   caddishness, callosity, callousness, callus, casualness,
   coarseness, coldbloodedness, coldheartedness, coldness, crudeness,
   crudity of intellect, deadness, discourteousness, discourtesy,
   dullness, electronarcosis, flintiness, formidable defenses,
   gross behavior, grossness, hard heart, hard shell, hardenedness,
   hardheartedness, hardness, hardness of heart, heart of stone,
   heartlessness, ill breeding, ill manners, impassibility,
   imperception, imperceptiveness, imperceptivity, impercipience,
   imperviousness, impoliteness, imprudence, incivility,
   inconsiderateness, indiscreetness, indiscretion,
   indiscriminateness, indiscrimination, induration, insensibility,
   insensibleness, insensitiveness, insentience, inurbanity,
   inuredness, lack of feeling, lack of refinement, loutishness,
   mannerlessness, narcosis, narcotization, numbness, obduracy,
   obdurateness, obtuseness, offensiveness, pins and needles,
   pitilessness, promiscuity, promiscuousness, rhinoceros hide,
   rudeness, stoniness, syncretism, tactlessness, thick skin,
   uncourtliness, uncriticalness, undiscriminatingness,
   undiscriminativeness, unfastidiousness, unfeeling, unfeelingness,
   ungallantness, ungentlemanliness, ungraciousness, unmannerliness,
   unmercifulness, unmeticulousness, unnaturalness, unparticularness,
   unperceptiveness, unpoliteness, unpreciseness, unresponsiveness,
   unselectiveness, unsolicitousness, untactfulness, vulgarity