The Influence of Serotonin Deficiency on Choice Deferral and the Compromise Effect

Psychological and physiological states such as mood, hunger, stress, and sleep deprivation are known to affect decision-making processes and therefore crucially influence consumer behavior. A possible biological mechanism underlying the observed variability of consumer behavior is the context-sensitive variation in the levels of neuromodulators in the brain. In a series of four experimental studies, the authors pharmaceutically reduce the levels of the neurotransmitter serotonin in the brain to diminish the availability of subjects’ cognitive resources. In doing so, they study how serotonin brain levels influence (1) subjects’ tendency to avoid buying and (2) consumers' preference for product options positioned as a compromise in a given choice set rather than for more extreme alternatives (i.e., the compromise effect). Using realistic product choice scenarios in a binding decision framework, they find that a reduction of brain serotonin levels leads to choice deferral and decreases the compromise effect, both as a within-subjects and as a between-subjects choice phenomenon. As such, this study provides neurobiological evidence for the assumption that the compromise effect is the result of deliberate and demanding thought processes rather than intuitive decision making.