Preferences influence all aspects of human behaviour; they impact upon the foods we eat, the products we buy, the stimuli we approach or avoid and the people with whom we spend time . Evaluation of stimulus valence is so fundamental that it has been proposed that the brain uses it as a basic category for organizing information and activating approach or avoidance behaviors. Stimulus evaluation is also thought to be immediate, unintentional and linked to behavioral responses.
Andy P. Field, in an article to be published in Behaviour Research and Therapy, writes that childhood is undoubtedly a prime period for developing preferences (if only because as age increases the proportion of novel stimuli in the environment decreases) and the importance of studying developmental aspects of attitude formation has been alluded before. Although little is known about how preferences develop in childhood, work in adults suggests that evaluative responses to stimuli can be acquired through classical conditioning.
In the study, available online since May 2005, two experiments were conducted with the purpose to develop a paradigm to test unequivocally whether stimulus evaluations can be conditioned in children. In the two experiments children were exposed to novel cartoon characters, that were either consistently paired with a picture of a disliked food (Brussels sprouts) or a liked food (ice cream). In the first experiment, relative preferences for these stimuli (and others) were measured before and after these paired presentations: preferences for the cartoon character paired with Brussels sprouts decreased, whereas preferences for the character paired with ice cream increased. These preferences persisted after 10 un-reinforced trials. The second experiment replicated this finding using affective priming as an index of preference for the cartoon characters.
These findings demonstrate that preferences to novel stimuli can be conditioned in children and result from associations formed between the stimulus and a stimulus possessing positive or negative valence.