APA Dictionary of Psychology

n. a circular depiction of the similarities among multiple variables. For example, a researcher studying emotions might focus on certain core affects and create a circumplex representation of them, with variables having opposite values or characteristics (i.e., tranquility–frenzy; sadness–enthusiasm; sluggishness–excitement) displayed at opposite points on the circumplex, whereas variables having highly similar characteristics are displayed adjacent to one another on the circumplex. In other words, the similarity (and correlation) between elements declines as the distance between them on the circle increases.