The factor that is not a plausible explanation for the Flynn Effect is a. deterioration in educational opportunities for middle-class families. This is because the Flynn Effect refers to the observed increase in intelligence test scores over time, and there is no evidence to suggest that educational opportunities for middle-class families have deteriorated over the same time period. On the contrary, access to education has generally improved in many countries, and this may be one of the factors contributing to the Flynn Effect. The other three options listed (increased exposure to new technologies, increased societal emphasis on abstract problem solving, and improvements in the lives of low-income families) are all plausible explanations for the Flynn Effect.