The Weird Things That Correlate With Intelligence

Higher childhood cognitive scores have been linked to greater odds of later reporting use of some illegal drugs. Higher early-life scores have also predicted lower mortality. Why can both findings be true—and what would be wrong with combining them into a personality type?

Starting with the height–IQ question, this conversation explores brain volume, nearsightedness, curiosity, drug experimentation, longevity, vegetarianism, trust and an uncertain semen-quality finding. Small effects, imperfect labels and replication change the story.

This is a public science discussion, not a way to estimate anyone’s IQ. Associations do not establish causes. Sources were independently checked; synthetic dialogue was generated with NotebookLM and edited and reviewed for accuracy.

Sources

• Height: Beauchamp et al. (2011)
• Brain volume: Pietschnig et al. (2022)
• Myopia: Megreli et al. (2020)
• Personality: Anglim et al. (2022)
• Drug use: White, Gale & Batty (2012)
• Separate drug cohort: White & Batty (2012)
• Mortality review: Calvin et al. (2011)
• Vegetarianism: Gale et al. (2007)
• Trust: Sturgis, Read & Allum (2010)
• US vocabulary/trust: Carl & Billari (2014)
• Semen: Arden et al. (2009)
• Semen replication: DeLecce et al. (2020)