Is Intelligence All In Your DNA? One New Study Sheds Light On The Topic.

A person’s capacity for intelligence is a complex issue that clearly depends on a variety of factors including genetics, but scientists haven’t been able to pinpoint exactly how much of our intelligence is hardwired in our DNA.

We might be closer to figuring it out, however, thanks to the research of psychologists Nancy L. Segal and Elizabeth Pratt-Thompson.

Nature vs. nurture

IQ tests might not be a perfect measure of a person’s intelligence, but the Wechsler examination is highly respected among academics and provided a baseline for this report.

The findings were published in the peer-reviewed Personality and Individual Differences journal, outlining the impact of both genetic and environmental influences on individuals over the course of years.

The researchers focused on three groups of subjects:

• 15 pairs of young Chinese monozygotic twins raised apart from each other
• 12 pairs of adult Danish monozygotic twins raised apart from each other
• 43 pairs of “virtual” or unrelated twins raised together in the same home

And after comparing changes in the IQ test results after two examinations, the researchers reached a conclusion regarding how, and to what extent, genetics helps determine a person’s intelligence.

The effects of time

When studying the virtual twins, Segal and Pratt-Thompson found that their IQ levels moved further apart in the second test. On the other hand, the related twins — both in China and Denmark — saw their respective IQ levels grow closer as time elapsed.

The result, according to the study, seems to be that environmental factors are very important during the early years. But over the course of a person’s life, the impact of genetics plays an increasingly significant role.

“Home factors are more important when we are younger, but as we age we select opportunities and events that align with our genetic potentials,” Segal explained.

Chris Agee July 11th, 2024

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