Dipartimento di Psicologia Generale | Università di Padova | Italy

**Peter Kramer, Paola Bressan, Massimo Grassi**

**Abstract**

Performing mental subtractions affects time (duration) estimates, and making time estimates disrupts mental subtractions. This interaction has been attributed to the concurrent involvement of time estimation and arithmetic with general intelligence and working memory. Given the extant evidence of a relationship between time and number, here we test the stronger hypothesis that time estimation correlates specifically with mathematical intelligence, and not with general intelligence or working-memory capacity.

Participants performed a (prospective) time estimation experiment, completed several subtests of the WAIS intelligence test, and self-rated their mathematical skill. For five different durations, we found that time estimation correlated with both arithmetic ability and self-rated mathematical skill. Controlling for non-mathematical intelligence (including working memory capacity) did not change the results. Conversely, correlations between time estimation and non-mathematical intelligence either were nonsignificant, or disappeared after controlling for mathematical

intelligence.

We conclude that time estimation specifically predicts mathematical intelligence. On the basis of the relevant literature, we furthermore conclude that the relationship between time estimation and mathematical intelligence is likely due to a common reliance on spatial ability.

Kramer, P., Bressan, P., & Grassi, M. (2011). Time estimation predicts mathematical intelligence. PLoS ONE, 6(12): e28621.

See original paper on the PLoS ONE website (the pdf can be downloaded for free)

*Why is our research important?*

Estimating beep durations requires no calculation. Yet, we found that the best duration estimators tend to have the highest mathematical intelligence. What most likely underlies both time estimation and mathematical ability is a tendency to mentally represent quantities in a spatial way. Encouraging this tendency might help improve mathematical intelligence, satisfying one of modern society’s greatest needs.

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• read coverage in Inkfish (“Why good time estimators are better at math”, 8 December 2011)