What is rare is the average age when these individuals started working and investing in stocks—15 and 25 years old, respectively. Both of these figures are unusual given that the basic minimum age for employment is generally 16 years, and, according to a Fed report, only 13.8 percent of U.S. households own stocks.

The survey also sheds some light on how these individuals accumulated so much wealth. On average, the survey’s respondents estimated that 52 percent of their wealth came from income, while 10 percent came from inheritance, and 32 percent from investments. Other reports on wealthy Americans suggest that a lot of this wealth goes into savings. It’s in adulthood when the personal savings gap between average Americans and wealthier ones seems to widen significantly. Data from the U.S. Bureau of Economic Analysis indicates that the national personal saving rate—the percent of a person’s disposable income that goes into savings—is currently 5.4 percent. However, for America’s wealthiest 1 percent, that rate is as high as 51 percent.

So why are the wealthy so good at saving money? It’s not just that they have ample funds to do so. Researchers who study the wealthy have long suspected that it might have something to do with the way wealthier parents teach their children about money, which then shapes their financial lives well beyond childhood. While most of the respondents in the Bank of America report said they grew up in a middle-class household, 68 percent of these wealthy individuals, when asked about their parents’ values, said that their families prioritized financial discipline nearly as much as academic achievement (and way ahead of things like civic duty, creative expression, or athleticism).

A broader question is whether saving up one’s riches helps or hurts the economy at large. Personal-finance experts may lament how low America’s savings rate is, but macroeconomists worry that a spike in savings could mean a slowdown in consumer spending. A McKinsey report estimated that each percentage point increase in the savings rate translates into $100 billion less of consumer spending if incomes fail to rise. If being or becoming wealthy has a lot to do with not spending money, that’s potentially worrying for economic growth.

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