Methods

Participants

All participants were UCSD undergraduate students receiving class credit. Only those with normal or corrected vision were included.

Materials

Two sets of stimuli were prepared for this experiment: pictures of food along with corresponding recipes for each condition and face morphs. The food stimuli set consisted of 60 pictures paired together as unusual food combinations (chicken and chocolate). These 30 combinations were accompanied by two opposing recipe results: good and bad (chicken mole and chicken with chocolate syrup).

A total of 70 face morph pictures from four different categories of faces morphed across race and gender were presented. Multiple morphs across neither factor, one, or both factors were used ranging from simple to complex blends, respectively. For example, a face morphed from two faces sharing the same race and gender would be a simple blend and a face morphed from two faces of different races and gender would be a complex blend.

Design and Analysis

This experiment has two independent variables: mindedness priming type (no prime for control, good recipe for open-minded or bad recipe for narrow-minded) and rating type (attractiveness scale or major attribution task). Priming type was manipulated between subjects and rating type was manipulated within subjects and counterbalanced between rating phases.

Procedure

Attractiveness ratings and perceptual fluency were assessed through the random assignment of three conditions: control, open-minded, and narrow-minded. Participants in the control condition did not receive the priming of food stimuli and only rated face morphs across both rating types. Participants in the narrow-minded and open-minded conditions were presented with a priming phase three blocks in length and a rating phase seven blocks in length. The entire experiment consisted of ten of these sets.

Participants were assessed individually in small rooms with normal lighting. The experiment was administered using a computer program that advances with user input.

The learning phase primed the participant with pictures of two food items designed to be unlikely combinations along with a questions, such as ‘what can you make with these foods?’. Depending on the condition, participants would then be given a recipe combining the ingredients to result in either a tasty meal for the open-minded condition or a nasty meal for the narrow-minded condition. After the presentation of the recipe, participants would be asked a question unrelated to the attractiveness of the food (‘how difficult is this recipe?’) then moved on to the next block.

The rating phase recorded the effects of the learning phase on overall perceptual fluency and categorical averageness effects. Participants were shown face morphs presented as actual faces counterbalanced in order of complexity, while showing at least one face from each complexity category. Depending on the rating task, participants would be asked to rate these faces on an attractiveness scale or to attribute a college major to the face. The attractiveness scale ranged from 1-9, nine being the most attractive. The face would be presented and remain on screen while the scale would appear and the participant would rate the face. For the major attribution task, a face would be presented first on the screen. Then two choices of well known college majors (theatre and engineering) would appear next to the face on either side. Finally, a sentence revealing relevant information (“many of my text books are plays”) about the student pictured would appear above the face. At this point, participants were able to choose a major for the student. Reaction time was recorded from the moment participants were free to attribute the major until the correct answer was given.