Popular depictions of "poor people" almost always include some sort of disability to drive home the "otherness," and mental or intellectual disability is commonly seen as a consequence. However, there is significant research to suggest that people living at or under poverty lines are at increased risk of developing or passing on an intellectual disability. This can be traced to reduced options regarding healthcare, education, living standards, and general safety.An article by E. Emerson states in the abstract:
...poverty causes intellectual disabilities, an effect mediated through the association between poverty and exposure to a range of environmental and psychosocial hazards.
(Emerson, "Poverty and People...", PubMed)
In other words, those living in poverty suffer reduced living standards, including general safety in their city or building, and the hazards of contaminated food, drink, and air. This connection realizes that people living in poverty do not have the opportunities enjoyed by others; their living standards are such that they cannot keep from being harmed by their environment, not to mention the social stigma of poverty, which can cause lasting mental damage. This means that poverty encourages intellectual disability even as it prevents sufferers from escaping those hazards.The abstract further states:
...families supporting [a person] with intellectual disabilities ... are at increased risk ... due to the financial and social impact of caring and the exclusion of people with intellectual disabilities from the workforce.
This serves to heighten the preceding statement, as a family with an intellectually disabled member might find themselves sliding into the poverty line directly because of that member, either because of financial costs or because of social stigma. Even today it is difficult for an intellectually disabled person to find gainful employment, a discrimination which is justified by employers by simply not giving reason. In turn, that family might find itself threatened by the very social and environmental hazards mentioned above because of their new status as poverty-stricken, increasing the chances (as stated above) of continuing the cycle.
Overall, this means that the state of poverty increases the chances of intellectual disability, just as being intellectually disabled increases the chances of poverty; correlation and causation strengthen each side, both harming the individual and family unit.
The cycle of poverty and disability, both physical and intellectual, is difficult to fix from the outside, and from the inside can seem impossible to escape. Both social mores and personal ambition must work and change to rescue people in need and provide a solid, gainful future, no matter what the mental or financial state of the sufferer.