Disabilities, physical and mental
Being disabled is the state of being physically or mentally less developed or incomplete. Some misinformed Buddhists believe that to be disabled must be the result of having done something negative in a former life. Such a belief is a good example of what can be called kammic naivety.
Positive or negative kamma manifests itself as either positive or negative feelings. In reality, a person with a physical handicap can be as happy as a fully developed person, sometimes more so. It has likewise been observed that people with Downs Syndrome are often gentle, loving and innocent, in stark contrast to some 'normal' people. We may see a disabled person and think: 'I would not like to be like that' but our own feelings are no indicator of theirs. It is quite possible that a disabled person could accept their condition and be happy, content and fulfilled. This being so, it is an unsafe generalization to say that being physically or mentally disabled is the result of having done something negative in the past. Science has demonstrated that most disabilities are due to a genetic fault and thus from the perspective of Buddhist doctrine, have their cause in biological and physical laws (bīja niyāma and utu niyāma), not kamma.
Some of the Buddha's disciples were physically disabled - Khujjuttarā was a hunchback and Bhaddiya was a dwarf. The first was praised by the Buddha for her great learning (A.I,26) and the second for his beautiful voice. Khujjuttarā attained the first stage of enlightenment and Bhaddiya became fully enlightened (S.II,279). Clearly, being physically disabled is no barrier to spiritual attainment. The Buddha made it an offence for monks or nuns to mimic physical disabilities (yathāvajjena kīḷanti, Vin.III,179).