Dominance and prestige as differential predictors of aggression and testosterone levels in men

Abstract

The relationship between self-esteem and aggression has yielded mixed results and generated much recent debate in the social psychology literature. Based on an evolutionary-psychological theory of self-esteem, Kirkpatrick et al. [Kirkpatrick, L. A., Waugh, C. E., Valencia, A., Webster, G., 2002. The functional domain-specificity of self-esteem and the differential prediction of aggression. Journal of Personality and Social Psychology 825, 756–767] showed that multiple, functionally distinct self-esteem mechanisms predict aggression differentially: e.g., “self-perceived superiority” is positively related, and “social inclusion” inversely related, to behavioral aggression. The present study extends this research by further differentiating two distinct forms of “superiority,” dominance and prestige [Henrich, J., Gil-White, F. J. 2001. The evolution of prestige: Freely conferred deference as a mechanism for enhancing the benefits of cultural transmission. Evolution and Human Behavior 22, 165–196], in the prediction of aggression in men and women and testosterone levels (measured in saliva samples) in men. Dominance was positively related, but prestige was either unrelated or inversely related, to self-report aggression measures. Dominance was unrelated but prestige inversely related to testosterone levels in men, perhaps suggesting a method of testosterone inhibition in individuals attaining prestige-based superiority. In addition to contributing to the growing literature on the aggression–self-esteem link, the results provide validation for the prestige–dominance distinction and support, but also suggest an important refinement to, a theory of self-esteem as a collection of functionally distinct adaptations.

Introduction

Much attention in recent years has been focused on the relationship between self-esteem (SE) and aggression, with the empirical literature evincing highly mixed results (Baumeister & Boden, 1998, Baumeister et al., 1996). Based on an extensive review of this literature, Baumeister et al. (Baumeister & Boden, 1998, Baumeister et al., 2000) conclude that SE per se is unrelated to aggression, arguing instead for a model of aggression involving ego threat and narcissism.

Alternatively, Kirkpatrick, Waugh, Valencia, & Webster (2002) have argued for an understanding of this relationship based on an evolutionary theory of SE as comprising multiple mechanisms with multiple distinct functions (Kirkpatrick & Ellis, 2001), each of which may be related to aggression in different (and adaptive) ways. Kirkpatrick etal. (2002) demonstrated empirically that domain-specific SE measures were differentially predictive of aggression in the laboratory—in some cases in opposite directions—whereas global SE was unrelated to aggression. The present research was designed to extend this line of research by (1) further distinguishing dominance vs. prestige as functionally distinct components of SE and (2) examining the relationship of these measures to aggression as well as examining the role testosterone may play in predicting SE components.

Most conventional theories in social and personality psychology conceptualize SE largely as a desired end-state—that is, something toward which people are motivated to strive. In contrast, Leary and Downs (1995) have argued that SE is a self-evaluative mechanism, analogous to the fuel gauge on a car's dashboard, that monitors the current status of one's social relations. Specifically, they argue from an evolutionary perspective that because inclusion in social groups has been crucial for survival and reproduction throughout human history, SE reflects an adaptation designed to monitor one's level of social inclusion or acceptance and to motivate corrective action when this falls below an acceptable threshold.

Kirkpatrick and Ellis (2001) extended this model by arguing that (1) because social inclusion in groups is only one of many functionally distinct adaptive problems presented by group living, SE should comprise numerous, functionally independent sociometers related to different social domains; and (2) these sociometers serve a variety of adaptive functions other than merely motivating corrective action. For example, in addition to monitoring inclusion within cooperative social relationships such as friendships and coalitions, as emphasized by Leary and Downs, people must monitor their relative standing in competitive relationships (e.g., for mates and status) in order to adaptively regulate their behavior toward others below vs. above oneself in a hierarchy (Leary & Baumeister, 2001).

This functional, evolutionary model of SE leads to the hypothesis that the relationship between SE and aggression might vary considerably across different SE domains. For example, it generally is adaptive for larger and stronger individuals to use (or threaten) aggression against weaker rivals, and for subordinates to avoid such conflicts; consequently, individuals in many species appear to assess their own and rivals' relative resource-holding power (RHP; Parker, 1974) and regulate their behavior toward competitors accordingly. Other domains of SE would be expected to relate to aggression differently: for example, high levels of social inclusion should be inversely related to aggression given the disruptive nature of aggressive behavior to cooperative social relationships.

Kirkpatrick et al. (2002) demonstrated exactly this differential pattern of empirical relationships between SE domains and aggression in college students. In their first study, a general measure of self-perceived superiority predicted higher aggression, whereas social inclusion predicted lower aggression, in a laboratory paradigm. In a second study designed to create a mate-competition context, high self-perceived mate value emerged as a positive predictor of aggression. Global SE was unrelated to aggression in both studies. Webster and Kirkpatrick (2006) have recently replicated many of these findings using both self-report and behavioral measures of aggression, with mate value and social inclusion predicting aggression differentially.

Although Kirkpatrick et al. (2002) succeeded in distinguishing a competitive form of SE (self-perceived superiority) from a cooperative (social inclusion) form, the former construct may also be too broad. According to Henrich and Gil-White (2001), hierarchies of human status or rank (i.e., differential access to valued resources) can be based upon either of two distinct strategies or processes: Dominance refers to the attainment of status or rank through the use or threat of force, whereas prestige refers to status that is bestowed freely by others upon those displaying valued skills, knowledge, or abilities. Kirkpatrick and Ellis (2006) have since revised their model to include separate sociometers related to these distinct competitive processes.

This dominance–prestige distinction has important implications for understanding the SE–aggression link. Aggression, or the threat thereof, is inherent in dominance competition; as noted previously, high self-perceived dominance should increase the likelihood of aggression. In contrast, aggression is generally anathema to the maintenance of prestige (as with social inclusion): The display of aggression by high-prestige individuals runs the risk of driving away followers (or clientele; Henrich & Gil-White, 2001). The measure of “self-perceived superiority” employed by Kirkpatrick et al. (2002) conflates these two competitive forms of SE. The present study was therefore designed to assess self-perceived dominance and prestige separately and examine their respective predictive relationships with aggression.

A secondary goal of this research was to examine the distinction between dominance and prestige using a physiological measure that may reflect one of the proximal mechanisms underlying any SE–aggression relationships. Testosterone (abbreviated T) is a steroid hormone produced and secreted in the thecal cells of the ovaries, the Leydig cells of the testes, and in cells in a portion of the adrenals (Lindzey & Korach, 1997). T is a member of a larger group of steroid molecules known as androgens, which have powerful organizational effects in multiple brain regions. Androgens are known to modulate the size and structure of brain nuclei related to emotional and cognitive processing including the medial amygdala (Johansen et al., 2004, Morris et al., 2005) and the sexually dimorphic nucleus of the preoptic area in the anterior hypothalamus (Morris, Jordan & Breedlove, 2005). Generally speaking, androgens are thought to act as signals to induce cell death or proliferation in these regions; however, the exact signaling pathway is unclear.

Empirical relationships between T and aggressive behavior are conflicting but well documented (Book et al., 2001, Harris et al., 1996, Olweus et al., 1988; see also Archer, Graham-Kevan, & Davies, 2005; see Giammanco, Tabacchi, Giammanco, Di Majo, & Guardia, 2005 for a review). Where direct measures of aggressiveness are available (i.e., nonhuman animal subjects), testosterone is related to aggressive behavior (Lumia, Thorner, & McGinnis, 1994). However, for obvious ethical reasons, research investigating testosterone and aggression in human subjects is more restricted and perhaps as a result the relationship between the two variables is not as certain (O'Connor, Archer, Hair, & Wu, 2002; see also Giammanco et al., 2005). Additionally, testosterone has been shown to fluctuate in response to environmental cues such as competition or challenge (Neave & Wolfson, 2003, Salvador et al., 2003, Wagner et al., 2002; see Archer, 2006 for a review). Furthermore, in both human (Newman, Seller, & Josephs, 2005) and nonhuman subjects (Briganti et al., 2003, Mitchell & Wilson, 1987), testosterone appears to interact or respond to social rank. Considering the relevance of behaviors such as competition, social rank, and aggression to dominance, we expected T levels to be differentially related to measures of dominance and prestige with individuals high in dominance exhibiting higher testosterone levels than individuals high in prestige.