Poor nutrition and medical care, poor living conditions (older, cheaper buildings often have lead paint on the walls), and a lack of intellectual support are thought to lead to .

Familial re-tar-dation, is the right answer.

Explanation:

Familial Re-tar-dation is also known as cultural-familial or socio-cultural re-ta-rdation. It is a state of mental re-tardation which is believed to emerge as a consequence of environmental factors. It is generally associated with some sorts of psycho-social disadvantages such as poor diet, lack of pren-atal care and intellectual stimulation, instead of a neu-rological reason.

c. wright mills's sociological imagination suggest investigating to explain this increase?