Interpersonal interactions and relationships can be described as unfolding along two perpendicular dimensions: verticality (power, dominance, control; Burgoon & Hoobler, 2002; Hall, Coats, & LeBeau, 2005) and horizontality (affiliativeness, warmth, friendliness; Kiesler, 1983;Wiggins, 1979). The vertical dimension refers to how much control or influence people can exert, or believe they can exert, over others, as well as the status relations created by social class, celebrity, respect, or expertise. Numerous earlier authors have discussed variations and differences within the verticality concept (e.g., Burgoon & Dunbar, 2006; Burgoon, Johnson, & Koch, 1998; Ellyson & Dovidio, 1985; Keltner, Gruenfeld, & Anderson, 2003).
Social control aspects are prevalent in many social relationships and interactions, not only in formal hierarchies such as in the military or in organizations; there is also a difference in social control between parents and their children, and husbands and wives can have different degrees of power in their relationships. Even within groups of friends or peers, a hierarchy emerges regularly.
Verticality encompasses terms such as power, status, dominance, authority, or leadership. Although different concepts connote different aspects of the vertical dimension, their common denominator is that they are all indicative of the amount of social control or influence and thus of the vertical dimension. Structural power or formal authority describes the difference in social control or influence with respect to social or occupational functions or positions (Ellyson & Dovidio, 1985) (e.g., first officer). Status refers to the standing on the verticality dimension stemming from being a member of a specific social group (e.g., being a man versus a woman) (Pratto et al., 1994). Status also means being awarded a high position on the verticality dimension by others (e.g., emergent leader) (Berger, Conner, & Fisek, 1974). The term dominance (also authority) is used to describe a personality trait of striving for or of having high social control (Ellyson & Dovidio, 1985). Dominance is also used to denote behavior that is aimed at social control (Schmid Mast, 2010). Leadership is the influence on group members to achieve a common goal (Bass, 1960). In a given social situation, different verticality aspects can either converge or diverge. A company leader has high structural power but his or her interaction or leadership style can express more or less dominance.