Is personality more important than intelligence? This replication says no, but it’s as always more complicated.

In 2016 a study by Borghans, Golsteyn, Heckman and Humphries stated that

on average, grades and achievement tests are generally better predictors of life outcomes than “pure” measures of intelligence. The reason is that they capture aspects of personality that have been shown to be predictive in their own right. All of the standard measures of “intelligence” or “cognition” are influenced by aspects of personality, albeit to varying degrees, depending on the measure.

Now there is a replication study by Zisman and Ganzach that refutes this claim:

We conduct a replication of Borghans, Golsteyn, Heckman and Humphries (PNAS, 2016) who suggested that personality is more important than intelligence in predicting important life outcomes. We focus on the prediction of educational (educational attainment, GPA) and occupational (pay) success, and analyze two of the databases that BGHH used (the NLSY79, n = 5594 and the MIDUS, n = 2240) as well as four additional databases, (the NLSY97, n = 2962, the WLS, n = 7646, the PIAAC, n = 3605 and the ADD health, n = 3553; all databases are American except of the PIAAC which is German). We found that for educational attainment the average R2 of intelligence was .232 whereas for personality it was .053. For GPA it was .229 and .024, respectively and for pay it was .080 and .040, respectively.

Although the original authors don’t agree, stating that the replication puts emphasis on one of the findings in our work and disregards its main message.
The main message of our work is that the Armed Forces Qualification Test should not be used as a measure of intelligence. This is not a narrow view of intelligence, but the main insight of our work.
And they see the results as evidence for their original findings:

Whether personality or intelligence is more important in predicting life outcomes is an important research question. ZG add interesting new evidence to this line of research. This comment on their work does not intend to disregard or devaluate these findings. Their work—based on measures of intelligence that are affected by personality—in fact confirms our work on the power of personality. Their work supports our claims rather than refutes them. It corroborates our message that scores on achievement tests should not be used as measures of intelligence because they are partly determined by personality.

Stankov wrote an article comparing both studies, but it was published in a predatory journal.

What could be the takeaways IMHO?

  • Intelligence still is a better predictor for success
  • The Big Five isn’t that much
  • There will probably be a link between intelligence and personality traits, but this link probably can go both ways.

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