Telling things apart : the distance between response keys influences categorization times

People use spatial distance to talk and think about differences between concepts. Using space to think about different categories is argued to scaffold the categorization process. In the current study we investigated the possibility that the distance between response keys can influence categorization times in binary classification tasks. In line with the hypothesis that the distance between response keys can facilitate response selection in a key-press version of the Stroop task, we found that the Stroop interference effect was significantly reduced when participants performed a Stroop task with response keys far apart, compared to when participants performed a Stroop task with response keys located close together. These results support the assumption that the spatial structuring of response options facilitates categorizations that require cognitive effort, and that people can incorporate environmental structures such as spatial distance in their thought processes. Keeping your hands apart might actually help to keep things apart.