Seeing red? The effect of colour on intelligence test performance

A series of recent studies reported that seeing red was associated with poor intelligence test performance in university students. Here we test for the first time the effect of colour on intelligence test scores in an adult sample and across a large battery of ability tests. Overall 200 British adults completed Raven's matrices without colour manipulation (i.e. baseline assessment); afterwards, they viewed a string of letters and digits in either red or green before completing six additional ability tests (i.e. word fluency, logical reasoning, vocabulary, syllogisms, verbal reasoning, and knowledge) and rating their self-perceived performance for each measure. We found no evidence for an association between colour and intelligence test scores or self-perceived performance, before and after adjusting for intelligence at baseline. The discrepancy with previous findings is likely to be due to testing adult rather than student samples, which in turn has implications for the recruitment and selection of study samples in future intelligence research.