“Limited Evidence for the Effect of Red Color on Cognitive Performance: A Meta-Analysis”, Timo Gnambs2020 (, , , )⁠:

Red color supposedly affects cognitive functioning in achievement situations and impairs test performance. Although this has been shown for different cognitive domains in different populations and cultural contexts, recent studies including close replications failed to corroborate this effect.

Reported here is a random-effects meta-analysis of 67 effect sizes (38 samples) that compared test performance after viewing red or a control color. For anagram tests and knowledge tests no statistically-significant difference between color conditions was found (Cohen’s d of −0.06 and −0.04); for reasoning tests the pooled effect of d = −0.34, 95% CI [-0.61, −0.06] indicated statistically-significantly lower scores in the red condition.

The cumulative meta-analysis revealed substantially larger effects in initial studies as compared to subsequent research. After correcting for publication bias no evidential value for an effect of red color on intellectual performance was available.

The review casts doubt on the existence of a robust color-priming effect in achievement situations.