Income is the personal characteristic most often thought to be associated with differences in knowledge, expectations, and opinions about Social Security and wealth. For example, one would hypothesize that individuals with low incomes would be more likely than those with high incomes to (1) expect Social Security to be their major source of retirement income, (2) be less likely to own stocks or mutual fund shares, and (3) be renters rather than homeowners. Some of these hypotheses are based on income alone, but others are based on the almost axiomatic relationship between education and income—i.e., that persons with more education have higher incomes than those with less education. The income-education relationship also supports further speculation, such as the hypothesis that individuals with higher incomes would be more likely than those with lower incomes to know details about Social Security (e.g., eligibility ages for receiving partial and full retirement benefits).