Our paper investigates the underlying motivations of social interactions. By using a qualitative approach, we discuss the relevance of conditional (trust and reciprocity) and unconditional (altruism and inequality-aversion) motivations in investment games. Specifically, self-reported questionnaires and free subjects’ comments are used to discuss the coherence between observed behavior, declared motivations
and beliefs of participants. We find a strong coherence between experimental outcomes and the qualitative information obtained from participants. Both are consistent with motivations based on other-
regarding preferences.