Research has shown that parental socioeconomic status has a direct influence on children’s later status attainment, such as educational and occupational success. But what is the role of personality traits or intelligence? Can people who are born into poverty “catch up” on their peers born into affluence just through their personality traits or intelligence?  Or , do the rich get richer and the poor get poorer?  Damian and colleagues (1) investigated this interesting question with longitudinal data.

Rather than simply contrasting family background versus individual qualities, it is more interesting to look at different combinations of the two. That is to say, individuals with certain characteristics may do disproportionately better or worse depending on whether they were born into a more challenging or more privileged family context.

Three patterns can be distinguished in relation to individual difference and parental socioeconomic status [SES] when predicting attained status in adulthood:

(a)    the independent effects hypothesis (i.e., personality traits and intelligence have the same effect on status attainment for all people across parental SES levels);

(b)   the resource substitution hypothesis (i.e., the returns to personality traits and intelligence would be greater for people overcoming limited socioeconomic resources of their parents) and

(c)    the Matthew effect (2) hypothesis ( - i.e., “the rich get richer”; children raised in higher SES households will benefit more from personality traits and intelligence). 

Insight in what matters comes from the “Project Talent”, which is a large scale, longitudinal study in the United States developed by the American Institutes of Research (AIR). This is an ideal data set for studying how individual differences at an early age and parental SES impact status attainment later in life. The original survey was conducted in 1960 on a 5% representative sample of U.S. high school students. The 11­year follow­up recorded the students’ educational attainment, annual income, and occupational prestige.

Although the study’s research team did find some evidence for both the resource substitution and the Matthew effect hypotheses, the independent effects pattern is more appropriate when predicting status attainment from personality traits and background factors. Results show that personality traits and intelligence in adolescence, in addition to parental SES, indeed matter in predicting status attainment in adulthood. More precisely, the effects of certain personality traits are smaller than parental SES, while the latter is also smaller than the effect of  intelligence. In practical terms, although personality traits may help to overcome background disadvantage to a small extent, they do not usually lead to a “full catch­up” effect. The only individual difference that is able to do that was intelligence. Cognitive ability was found to be the compensatory factor that would make up for starting out life in difficult straits.

Thus, the American Dream resulting from personality, is more illusion than fact. One the other hand, the American Dream realized through intelligence is still alive and well. To put it more colorfully, the study’s authors adapted George Carlin’s humorous words: “The reason they call it the American Dream is because you have to be asleep to believe it”— unless – as was found – you happen to be extraordinarily intelligent.