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EXPERIMENT 1

Method

Overview. Four crossed-category groups were created using a shape-estimation task. These groups were overestimators who estimate large shapes best (group OL), overestimators who estimate small shapes best (group OS), underestimators who estimate large shapes best (group UL), or underestimators who estimate small shapes best (group US). In the active (but not the passive) condition all participants were allocated to group OL, thus, group OL was the double in-group, groups OS and UL were partial groups and group US was the double out-group. [...]

Participants and design. Thirty-two female undergraduates were allocated to the two cells of a 2 (intergroup context: active/passive) X 4 (categorization: group OL/group OS/group UL/group US) mixed design with repeated measures on the second factor. [...]

Procedure. [...] The experimenter explained that the task involved estimating the surface area of each of 16 different shapes of differing sizes and then typing in their responses (in square centimeters). [...] Following this task, participants in the passive intergroup condition were then told that it is possible to classify people’s estimates [...]. These classifications resulted in four possible crossed-category groups: overestimators who estimate large shapes best (group OL), overestimators who estimate small shapes best (group OS), underestimators who estimate large shapes best (group UL), or underestimators who estimate small shapes best (group US). Participants were not told which crossed-category group they belonged to and continued with the rest of the experiment. In the active intergroup condition, the computer ostensibly calculated the participants’ combined crossed classification and presented this on the screen (all participants in the active condition were allocated to group OL). [...] Participants in both conditions were then given a trait differentiation questionnaire and asked to guess which traits applied to each of the four possible crossed-categorization combinations. In the active condition a second questionnaire was administered concerning similarity to self [...]. In both conditions participants then completed liking and intergroup similarity measures. [...]

Dependent measures. There were four measures: liking, intergroup similarity, similarity to self, and trait differentiation. [...] The questionnaire required participants to circle either “yes” or “no” as to whether they believed past research to have shown each of 32 traits to be related to each of the different people with different shape-estimation abilities. [...] Participants then completed measures of liking and similarity to self (all 7-point Likert-type scales [...]. The final measure of differentiation asked participants to mark four crosses on a 100-mm line to indicate, in terms of distance apart on the line, how similar the four groups were to each other. [...]

EXPERIMENT 2

Method

Overview. Four crossed-category groups were created as in Experiment 1. Here, however, the intergroup context was active in all conditions. [...] All measures were identical to those used in Experiment 1.

Participants and design. Thirty-two female undergraduates were allocated to the two cells of a 2 (feedback: neutral/positive) X 4 (categorization: double in-group/partial group OS/partial group UL/double out-group) mixed design with repeated measures on the second factor. [...]

Procedure. [...] The task involved remembering the sequence of spatial positions in which an “X” appeared on a computer screen. The “X” appeared at random in any of the four corners of the computer screen eight times. The participant was required to type in the sequence of eight positions using keys labeled to represent each corner. This was repeated four times (i.e., a total of 32 trials) after which the computer ostensibly calculated, for each participant, an accuracy score (i.e., percentage correct) and ranking (position out of the 42 participants who had supposedly already completed the task). The score was 51 of 100 and the ranking 22nd of 42 in the neutral feedback condition, while in the positive feedback condition the score was 84 of 100 and the ranking 3rd of 42. [...] Following feedback and the questionnaire measuring affective state participants carried out the shape estimation (categorization) task on a Power Macintosh computer. This task and subsequent questionnaires were identical to those used in the active intergroup condition of Experiment 1.

Dependent measures. All questionnaires were identical to those used in Experiment 1 except that a measure of affective state was added. Following performance feedback participants were handed a questionnaire containing 14 adjectives and required to indicate the degree to which each adjective described their feelings (Not at all, 1; Very much so, 7). Seven items (happy, cheerful, good-tempered, pleasant, resourceful, clever, warm-hearted) were intended to capture participants’ affective state in general while seven (annoying, unfair, offensive, unpleasant, irritating, unpleasing, insulting) were intended to measure participants’ affective state towards the feedback they received concerning their performance on the spatial memory task. [...]