Affective influences on strategic interpersonal behaviour: experiments in the dictator and ultimatum games

Affect plays an important role in interpersonal behaviour, yet the role of moods in how people manage strategic social situations remains little understood. This thesis investigated the cognitive and behavioural consequences of affective states on behaviour in two strategic games, the dictator game (Studies 1 – 3) and the ultimatum game (Studies 4 – 9). Based on recent affect-cognition theories, it was predicted that positive mood, by generating a more internally focused processing style, should increase selfishness, and negative mood should increase fairness in decisions. Study 1 confirmed that happy mood increased selfishness when allocating raffle tickets in the dictator game, and Study 2 replicated this finding in a field setting. Study 3 showed that mood effects on selfishness were greater when an unfair norm was made salient. Study 4 found that happy people made more selfish allocations during the first and last trials of an eight-trial ultimatum game. Study 5 showed that providing information about a fairness norm moderated mood effects. In Study 6, real money was allocated and personal relevance was increased. Results now showed that sad mood increased selfishness, indicating that the personal relevance and value of allocations moderated mood effects. Mood also influenced processing latencies, indicating that mood-induced processing differences played a role in these effects. Study 7 confirmed that with realistic prizes in a field setting, sad proposers were again more selfish, suggesting an interaction between mood and personal relevance as reported by Forgas and Fiedler (1996). Studies 8 and 9 looked at the behaviour of responders in the ultimatum game, and found that happy responders were more likely to accept unfair offers (Study 8), and norms suggesting acceptance by others also increased the tendency to accept unfair offers (Study 9). These results are theoretically interpreted as consistent with the information processing effects of mood states, as suggested by Bless and Fiedler's (2006) accommodative-assimilative processing model, as well as the affect-priming theory and the Affect Infusion Model (Bower, 1981; Forgas, 1995, 2002). The findings are discussed in terms of their implications for current affect-cognition theories, and the relevance of the results for real-life strategic behaviours in interpersonal situations characterised by a conflict between selfishness versus fairness is considered