Disadvantage in physically disabled adults: an assessment of the causation and selection hypotheses.

An area survey of West Beirut provided the opportunity to study whether disadvantage among people with physical disabilities is attributed to social class of origin (causation) or is due to the social consequences of disability (selection and drift). Adults who were disabled from poliomyelitis in childhood were compared to West Beirut residents and to age and sex matched sibling controls. The typical finding of a substantially greater proportion of disabled people in the lower social class groups was noted. Their fathers were also over-represented in the lower social classes but to a lesser extent in the skilled manual group. The occupational mobility processes, both inter-generational and intra-generational, pointed to a trend towards skilled labor for disabled groups from all social classes, a finding different from the general population trends. Selection (failure to reach or keep expected position) was noted in the lower social classes while the downward drift (movement from higher to lower social class) for the disabled persons was seen in the upper social classes. Both the causation and the selection-drift hypotheses were supported by the findings.