The Shared Features Principle: If Two Objects Share a Feature, People Assume Those Objects Also Share Other Features

In this article we introduce the shared features principle, which refers to the idea that when 2 stimuli share 1 feature, people often assume that they share other features as well. This principle can be recognized in several known psychological phenomena, most of which were until now never considered to be related in this way. To illustrate the generative power of the principle, we report 8 preregistered studies (n = 1,614) in which participants completed an acquisition phase containing 3 stimuli: a neutral target, a positive source, and a negative source. Our results indicate that behavioral intentions, automatic evaluations, and self-reported ratings of a target object were influenced by the source object with which the target shared a feature. This was even the case when participants were told that there was no relation between source and target objects. Taken together, the shared features principle appears to be general, reliable, and replicable across a range of measures in the attitude domain. We close with a discussion of its theoretical implications, relevance to many areas of psychological science, as well as its heuristic and predictive value.