May be land allienation.... kama hii habari ni ya kweli then automatically itakuwa imekuwa proved, beyond reasonable doubts, kwamba eneo/ukanda huu wa dunia ndilo eneo lenye binadamu wajinga kuliko eneo lingine lolote duniani.
Scientific researches have to be conducted to prove the reasons for that behavior; is it a genetic issue? harmful materials (in the land? air? waters? grains? foods?); or what?