The following is an excerpt of the intervention methodology. For more information, please see the full text of the article on the publisher's website or through your institution's library.

Study 1

Participants Seventy-three Turkish students of various majors at Koç University in Istanbul volunteered to participate in the study. The sample consisted of 43 women (59%) and 30 men (41%) whose age ranged from 18 to 30 years (M = 21.8, SD = 2.00). [...]

Procedure and Measures The effects of moral-exemplars stories on openness to contact and outgroup attitudes were tested using a between-subjects factorial design with one experimental factor (moral exemplars) with three levels (ingroup moral exemplars vs. unrelated outgroup moral exemplars vs. baseline group). First, the participants were randomly assigned to one of three conditions and asked to read a text about certain historical events. In the first condition (ingroup moral exemplars), the text consisted of testimonies of Armenians who had been saved by Turks during the massacres of 1915. [...] In the second condition (unrelated outgroup moral exemplars), the participants were presented with a very similar text in which moral acts were performed by an unrelated national group in an unrelated historical context (Germans saving Jews during WWII). In the third condition (baseline group), the participants read a passage about international affairs that did not include any reference to the events mentioned in the two other texts. After reading the text, all the participants were asked to fill in a paper-and-pencil questionnaire in which they answered questions about their attitudes towards Turks and openness to contact with them. [...] we adapted a social-distance scale as a measure of openness to contact. [...] The participants indicated their answers on a 5-point Likert scale [...] The participants were asked to indicate their feelings towards Armenians on a thermometer scale where 0° signified very negative, cold feelings and 100° signified very positive, warm feelings.

Study 2

Participants One hundred university students of the Pedagogical University of Warsaw were recruited during their social psychology lecture. [...] The final sample consisted of 95 students (99% female, 1% male; age range: 22–32 years; M = 22.62; SD = 1.57). [...]

Design and Measures The study followed a between-subjects design with one experimental factor (moral exemplar) with two levels (moral exemplar vs. control condition). [...] At the beginning, they were randomly assigned to one of the two conditions and presented with a personalized story of a German soldier during the Nazi occupation of Poland. The participants in the moral-exemplars condition read a one-page narrative about a German officer [...] who witnessed the Nazi crimes on Poles and Polish Jews and engaged in several heroic actions [...] The participants in the control condition were presented with a short narrative reflecting common Polish representations of Germans in the context of WWII [...] Firstly, to ensure that the participants had read the passage, they were asked to summarize the text in one sentence. [...] Afterwards, the participants were asked to indicate on a scale ranging from 1 (completely immoral) to 7 (highly moral) whether the German officer described in the text acted in a moral or immoral way. The second part of the questionnaire focused on participants’ attitudes towards contemporary Germans. Three dependent variables were assessed: outgroup trust, outgroup attitudes, and openness to contact. Unless otherwise indicated, all the answers were provided on a 7-point scale (where 1 = I strongly disagree and 7 = I strongly agree). [...]

Study 3

Participants One hundred and forty-two Polish high school students were recruited during their history class. [...] The final sample consisted of 92 students (71% female, 29% male; age range: 15–18 years; M = 16.83; SD = .70). [...]

Design and Measures To examine whether information about the number of helping behaviors may influence the effect of moral exemplars, in the actual design we employed three levels of the experimental factor: control versus few moral exemplars versus many moral exemplars. The participants were randomly assigned to the control condition or to one of the moral-exemplars conditions. In the control condition, they were asked to read a short passage about the deportations and imprisonment of Poles carried by Russians in 1939–40. In the moral-exemplars conditions, the same text was followed by short stories about help offered by (many or few) Russians to Poles. [...] First, to ensure that the participants had read the passage, they were asked to summarize the text in one sentence. Next, the participants were asked to indicate whether the text pictured Polish-Russian relations in a reliable way. [...] Finally, the participants were asked to evaluate the attitudes of Russian nation towards Poles during WWII on a scale ranging from 1 (decidedly negative) to 7 (decidedly positive). In the second part of the questionnaire, the same dependent variables as in Study 2 were assessed: outgroup trust, outgroup attitudes, and openness to contact. All the answers were indicated on a scale ranging from 1 (I strongly disagree) to 7 (I strongly agree). [...]