If two people have the same IQ score, have they been measured as the same kind of intelligent?
They have the same score on that test. IQ is an operational definition of intelligence, not the construct itself (the Research Methods lessons on constructs and operational definitions apply here). Spearman’s g is a common factor across tasks (Myers & DeWall, 2021; Spielman et al., 2020). Two people with the same IQ can still differ on the subtests that produced the score. Standardization is what makes the number comparable: the same procedure, a norms group.
If average IQ scores have risen across generations, what does that do to a claim that a score is a fixed biological essence?
The Flynn effect is that rise. A score that moves with generation, schooling, and health is a poor candidate for a frozen essence. Heritability of IQ, when it is reported, remains a population statistic — the nature–nurture article already installed that brake. Figure 14.1 separates the construct, the factor, and the score so a later sentence cannot treat IQ as intelligence itself.
| Term | What it names |
|---|---|
| intelligence | The construct: capacity to learn, reason, solve problems |
| g | A common factor across cognitive tasks |
| IQ | A standardized test score; one operational definition |
Check yourself with a quick quiz
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References
- Myers, D. G., & DeWall, C. N. (2021). Psychology (13th ed.). Worth.
- Spielman, R. M., Jenkins, W. J., & Lovett, M. D. (2020). Psychology 2e. OpenStax.
Image and media credits
- Top image. Red and white puzzle cubes on a desk under a lamp. It sets the scene for this lesson on intelligence. Source: Created for this site with Grok Imagine (xAI), an AI image generator. License: Original image made for mattgaugerx.com.
