Effect of coloration on size perception

Data on response of 96 human subjects each presented with four cards with two grasshopper images of identical size and asked to indicate which if any of the images that was largest. Grasshoppers were either black, grey or striped. One of the cards showed one monomorphic pair (same colour) and three cards showed all three dimorphic combinations with different-coloured grasshoppers. The file includes information on participant (number only), and for each of the four cards the colour morph combination and the response.