The interpersonal circle or interpersonal circumplex is a model for conceptualizing, organizing, and assessing interpersonal behavior, traits, and motives. The interpersonal circumplex is defined by two orthogonal axes: a vertical axis (of status, dominance, power, ambitiousness, assertiveness, or control) and a horizontal axis (of agreeableness, compassion, nurturant, solidarity, friendliness, warmth, affiliation or love). In recent years, it has become conventional to identify the vertical and horizontal axes with the broad constructs of agency and communion. Thus, each point in the interpersonal circumplex space can be specified as a weighted combination of agency and communion.
Placing a person near one of the poles of the axes implies that the person tends to convey clear or strong messages (of warmth, hostility, dominance or submissiveness). Conversely, placing a person at the midpoint of the agentic dimension implies the person conveys neither dominance nor submissiveness (and pulls neither dominance nor submissiveness from others). Likewise, placing a person at the midpoint of the communal dimension implies the person conveys neither warmth nor hostility (and pulls neither warmth nor hostility from others).
The interpersonal circumplex can be divided into broad segments (such as fourths) or narrow segments (such as sixteenths), but currently most interpersonal circumplex inventories partition the circle into eight octants. As one moves around the circle, each octant reflects a progressive blend of the two axial dimensions.
There exist a variety of psychological tests designed to measure these eight interpersonal circumplex octants. For example, the Interpersonal Adjective Scales (IAS; Wiggins, 1995) is a measure of interpersonal traits associated with each octant of the interpersonal circumplex. The Inventory of Interpersonal Problems (IIP; Horowitz, Alden, Wiggins, & Pincus, 2000) is a measure of problems associated with each octant of the interpersonal circumplex, whereas the Inventory of Interpersonal Strengths (IIS; Hatcher & Rogers, 2009) is a measure of strengths associated with each octant.