Wealthier children score higher on intelligence, but quality parenting levels the playing field

An analysis of the TwinLIFE study data found that children from families of higher socioeconomic status tended to exhibit somewhat higher levels of intelligence, and tended to be slightly more emotionally stable and extraverted compared to their peers from low socioeconomic status families. The paper was published in the Journal of Genetic Psychology.

Personality traits influence many important life outcomes, including academic achievement, health, earnings, relationships, and the ability to cope with stress. Although these traits are often viewed as relatively stable, their development may be shaped by both inherited characteristics and the environments in which children grow up.

Parents can influence children’s personalities through their own traits and abilities, their parenting styles, the time they spend with their children, and the opportunities they provide. Family socioeconomic status, including income, education, and occupational prestige, may affect these influences by determining the resources available for children’s development. Children from more advantaged families tend to receive greater educational, emotional, and material support, although higher socioeconomic status does not always produce more favorable personality outcomes.

Study author Melchior Vella hypothesized that higher socioeconomic status is associated with more favorable personality development. If this is true, children from families with higher socioeconomic status would achieve higher scores on the “Big Five” personality traits—openness, conscientiousness, extraversion, agreeableness, and emotional stability—the author reasoned. Also, parents of higher socioeconomic status might be more likely to practice positive parenting styles and to show greater parental investment.

To check these hypotheses, the author analyzed data from the German Twin Family Panel (TwinLIFE). This is an ongoing 12-year behavioral genetic study focused on social inequality development. TwinLIFE collects data through face-to-face and Computer-Assisted Telephone Interviews (CATI) with same-sex twins and their families. The study recruited twins raised in the same family across four age groups – those born in 2009/2010 (Cohort 1), 2003/2004 (Cohort 2), 1997/1998 (Cohort 3), and 1990–1993 (Cohort 4).

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Data used in this study came from Cohort 2, which included twins aged 10 to 12 at the time of the data collection. The sample consisted of 392 monozygotic (identical) and 648 dizygotic (fraternal) twins. The analyses were based on data from the first wave, which was collected via face-to-face interviews.

The author of the study used data on participants’ socioeconomic background (based on family income and the highest education level of parents), personality traits (assessed using the Big Five Inventory, BFI-S), fluid intelligence (defined as the ability to reason and solve problems independently of prior experience, measured using the short version of the Culture Fair Test 20 R), parenting style (using custom-adapted scales), and parental time (measured through the frequency of family activities).

Results showed that children from families of higher socioeconomic status tended to have somewhat higher fluid intelligence compared to children from low socioeconomic status families. They also tended to be slightly more emotionally stable and extraverted, although the association with extraversion was modest. Additionally, parents from high socioeconomic status families tended to devote slightly more time to their children.

The study’s use of twin data allowed the researcher to isolate environmental influences from genetic inheritance. Because identical twins share nearly 100% of their DNA while fraternal twins share about 50%, comparing the two groups helps reveal which traits are shaped by upbringing rather than biology.

The data revealed that parental investments are equally effective regardless of a family’s socioeconomic background. In other words, when low-income parents are able to invest the same amount of time and positive parenting into their children, they yield the exact same developmental benefits as high-income parents. Furthermore, the study found that children from disadvantaged backgrounds actually benefit the most from this increased parental investment.

“The findings suggest that interventions targeting parental investments and fostering desirable personality traits could significantly enhance outcomes, particularly for disadvantaged children, thereby offering a promising avenue for improving child welfare and life outcomes,” the study author concluded.

The study contributes to the scientific understanding of the links between socioeconomic status and psychological characteristics. However, it should be noted that while the socioeconomic disparities in fluid intelligence were relatively pronounced, the differences in personality traits across socioeconomic backgrounds were minor by comparison.

The paper, “The Impact of Parental Background on the Big Five Traits and Intelligence: Evidence from a Twin Based Study,” was authored by Melchior Vella.