experimental method section

Experiment 1 In Experiment 1, participants were assigned to one of the two arbitrary groups, saw repeated and non-repeated positive and negative stereotypical statements about their in-group and out-group and evaluated stereotypical statements about both groups as “true” or “false”. We predicted that participants would rate repeated stereotypical statements about their in-group more frequently as “true” than any other stereotypical statements. Materials Dot Estimation Task. For minimal grouping purposes we used Ratner and Amodio (2013) Numerical Estimation Style Test (NEST). NEST includes 3 practice and 10 test trials. We presented a cluster of dots (consisting of 98-200 identical dots) following by a number estimation question in each trial. Stereotypes. We selected traits from Anderson (1968) and translated these traits to Turkish. An English language expert checked Turkish versions of the traits. Three Turkish language experts rated top 200 personality traits that have the highest meaningfulness score in the original study. These three experts agreed on 92 positive traits and 84 negative traits. Among those, for positive stereotypes we selected top 40 traits having the highest likeability rates and for negative stereotypes we selected 40 traits having the lowest likeability traits. For stereotypical sentences we used a very simple sentence structure that is the combination of group names (over-estimators or under-estimators) and the traits. We chose to keep the sentences as simple as the real stereotypes about real groups for face validity. Identification Measures. We followed Cameron (2004) for identification measures by including three dimensions of social identity; centrality, in-group affect, and ingroup ties. Therefore, we used a four-item measure (“I identify myself with other over-estimators/under-estimators”, “I see myself as an over-estimator/under-estimator”, “I am glad that I am an over-estimator/under-estimator”, “I have strong ties with other over-estimators/under-estimators”). We used a 7-point Likert scale for these items indicating 1= “totally agree” and 7= “totally disagree”. We also asked participants to choose the best option showing their relationship with their ingroup on Pictorial Item of Identity Fusion Scale (Swann et al. , 2009). Participants 96 undergraduate students (73 female, 22 male, 1 unspecified; Mage= 21, SDage= 1. 47) from various departments at Duzce University and Abant Izzet Baysal University participated in the study. They participated either voluntarily or for course credit. Only one student was omitted from data because s/he gave uniform answers showing that s/he did not pay attention to the task. Design Participants were assigned to one of the two groups randomly (i. e. , “over-estimators” vs “under-estimators”). All participants evaluated stereotypes from eight categories in a 2x2x2 within participants design: repetition (repeated vs. new), group (ingroup vs. outgroup), valence (positive vs. negative). Procedure The participants took part individually in the lab. welcomed, read the consent form and sit in front of the computer. There were basically three parts in this experiment; minimal group assignment, statement evaluation, identification measurements with demographics. In the first part of the experiment, the participant was presented Numerical Estimation Task (Ratner & Amodio, 2013). They were shown cluster of dots and asked to estimate how many dot they have seen. After three practice trials, they took 10 test trials. A false feedback was given on the computer screen as “please wait, now the computer program is calculating your results”. At the end of the first part of experiment, the participant was acknowledged randomly as she is an over estimator or under estimator. In the second part there were three phases. In the first phase, they were presented 40 statements in random order and instructed to remember these statements. In the second phase they were asked to judge 40 statements (20 new and 20 old) as true or false by pressing two assigned keys on the keyboard. In the third phase they were asked to rate the statement as seen or unseen in the first phase only for manipulation check purposes. In the last part of the experiment identification with the group measured through 4 items and Pictorial Identity Diffusion Scale. After demographics and political orientation questions participants were debriefed and thanked.