The study participants included over 18,000 children born the same week in 1958. In 1965, when the kids were seven years old, their parents filled out surveys to determine their childhood SES. The parents provided information on their type of job (professional, skilled or unskilled), whether the family rented or owned their home and how many rooms it contained.
Also at age seven, the children were rated for math and reading ability, both on standardized tests and by their teachers’ personal evaluations. At age eleven, the kids were given intelligence tests, and at age 16, they were asked about their motivation and perceived ability to do well in school.
Finally, at age 42, the participants were asked how much education they had ultimately completed and to provide their current SES by the same measures indicated above.
There was a definite correlation between both math and reading ability and SES at age 42. This was true even after accounting for childhood SES and intelligence. If achieving a high SES is your top priority, you'd better hope you were paying attention in second grade.
Ritchie, S., & Bates, T. (2013). Enduring Links From Childhood Mathematics and Reading Achievement to Adult Socioeconomic Status Psychological Science DOI: 10.1177/0956797612466268.