Similar to themes, labels are also important to learned categorical perception. Labels are “noun-like” titles that can encourage categorical processing with a focus on similarities. The strength of a label can be determined by three factors: analysis of affective (or emotional) strength, permeability (the ability to break through) of boundaries, and a judgment (measurement of rigidity) of discreteness. Sources of labels differ, and, similar to unsupervised/supervised categories, are either created or already exist. Labels affect perception regardless of their source. Peers, individuals, experts, cultures, and communities can create labels. The source doesn’t appear to matter as much as mere presence of a label, what matters is that there is a label. There is a positive correlation between strength of the label (combination of three factors) and the degree to which the label affects perception, meaning that the stronger the label, the more the label affects perception.