In Colore Veritas? Color effects on the speed and accuracy of true/false responses

In addition to their perceptual or aesthetic function, colors often carry conceptual meaning. In quizzes, for instance, true and false answers are typically marked in green and red. In three experiments, we used a Stroop task to investigate automatic green-true associations and red-false associations, respectively. In Experiments 1 and 2, stimuli were true statements (e.g., "tables are furniture") and false statements (e.g., "bananas are buildings") that were displayed in different combination of green, red, and gray depending on the experimental condition. In Experiment 3, we used true-related and false-related words shown in green, red, or gray. Participants had to indicate the validity (or semantic meaning) of each statement (or word) as fast and as accurately as possible. We expected that participants would perform best when they had to categorize green stimuli as "true" and red stimuli as "false". The prediction was only confirmed when green and red stimuli were presented within the same context (i.e., same experimental condition). This finding supports the dimension-specificity hypothesis which states that cross-modal associations (here: associations between color and validity) depend on the context (here: the color-context). Moreover, the observed color-validity effects were stronger when participants had to categorize single words instead of sentences and when they had to provide speeded responses. Taken together, these results suggest that controlled processing counteracts the influence of automatic color associations on true/false responses.