We propose a teaching activity aimed at promoting social values, such as trust and reciprocity, among undergraduate students in economics and related degrees. We present our pilot experience of what we call RED–‘Reading–Experiment–Discussion’, a three-step activity as part of a class of a specific module at the University of Valencia. During the Reading step, we encourage students to reflect, learn, and critically think about social values. In the second step, Experiment, students make decisions in a trust game experiment, a game created to measure trust and reciprocity in economic environments. Students then give opinions through a post-experiment questionnaire. Our research hypotheses are tested by using non-parametric methods. We also investigate the association between students’ decisions and their attitudinal and sociodemographic characteristics by linear regression analysis. Experimental data show that decisions on trust and reciprocity are dependent on earnings information and that, on average, females trust more than males. Finally, in the Discussion step, the learning is reinforced by sharing the readings about morals and the experimental decisions. In short, RED may be of great help in transmitting to students the role of social preferences in individual decision making.