Hierarchy incentivizes group members

One important function of hierarchy is that it serves as an incentive structure that motivates individuals to contribute to the group. Baumeister et al. argue that individuation allows the group to hold people responsible for their actions, rewarding desirable behaviors while sanctioning undesirable ones. Although monitoring others in order to praise or punish sometimes occurs informally among peers, functions such as evaluating group members, holding them accountable, and incentivizing them are primarily performed by higher-ranking group members, especially in large organizations (for reviews, see: Fiske Reference Fiske, Fiske, Gilbert and Lindzey2010; Magee & Galinsky Reference Magee and Galinsky2008). Supervisors and managers, rather than peers, are typically in charge of making decisions regarding raises and promotions. In addition, the mere existence of pay dispersion in a hierarchy can often compel people to work harder to achieve promotion (Shaw et al. Reference Shaw, Gupta and Delery2002).

In addition to the economic incentives discussed above, hierarchy also creates social incentives that motivate individuals to work hard for the group. In particular, people place a high value on attaining respect, or rising up the status hierarchy (Barkow Reference Barkow1975). Considerable research has shown that groups reward costly individual contributions to the group with social status which, in turn, motivates further contributions (e.g., Flynn et al. Reference Flynn, Reagans, Amanatullah and Ames2006; Halevy et al. Reference Halevy, Chou, Cohen and Livingston2012a; Hardy & Van Vugt Reference Hardy and Van Vugt2006; Willer Reference Willer2009). Thus, status conferral provides a relatively cheap method of ensuring that group members act in the group's best interest and that valuable group members are retained (Emerson Reference Emerson1962).

Hierarchy satisfies fundamental human needs

Beyond satisfying the needs of the group, hierarchy has also been shown to fulfill several fundamental human needs of its individual members. Baumeister et al. propose that group identification fulfills the need for affiliation, which is captured in the first step of their model. Although social connection is undoubtedly an important benefit of group formation for the individual, it is only part of the story. As mentioned earlier, hierarchy enables individual group members to fulfill their need for status, which enhances self-esteem and overall well-being (Anderson et al. Reference Anderson, Hildreth and Howland2015). Meritocratic hierarchies further satisfy the needs for achievement and fairness by providing individuals with opportunities to advance based on personal deservingness (McCoy & Major Reference McCoy and Major2007). Additionally, hierarchy fulfills the desires for order and control by imposing structure on what otherwise would be seen as a random and unpredictable world (Friesen et al. Reference Friesen, Kay, Eibach and Galinsky2014). Hierarchy's ability to satisfy these fundamental human needs underlies the documented preference for hierarchical group structures over more egalitarian ones (Tiedens & Fragale Reference Tiedens and Fragale2003; Tiedens et al. Reference Tiedens, Unzueta and Young2007; Zitek & Tiedens Reference Zitek and Tiedens2012).

Hierarchy organizes and integrates group member contributions

Finally, hierarchy facilitates the process of coordinating group member contributions and integrating them into a cohesive whole. A large body of evidence has accrued showing that hierarchy can increase coordination in the types of groups that Baumeister et al. discuss, including sports teams (Halevy et al. Reference Halevy, Chou, Galinsky and Murnighan2012b), collective action groups (Simpson et al. Reference Simpson, Willer and Ridgeway2012), work groups (Ronay et al. Reference Ronay, Greenaway, Anicich and Galinsky2012), and even mountain climbing teams (Anicich et al. Reference Anicich, Swaab and Galinsky2015). Indeed, hierarchy has been put forth as not just important but crucial to solving social coordination problems in groups (de Kwaadsteniet & Van Dijk Reference De Kwaadsteniet and van Dijk2010; Van Vugt et al. Reference Van Vugt, Hogan and Kaiser2008). Legitimate hierarchy establishes clear expectations from leaders and followers. It delineates who gets to demarcate group boundaries (e.g., by having the authority to fire or hire); who gets to assign roles and work to others; and who makes the final decision when the group fails to reach consensus.

As Gruenfeld and Tiedens (Reference Gruenfeld, Tiedens, Fiske, Gilbert and Lindzey2010) contend, the proliferation of roles in organizations almost always coincides with a corresponding proliferation of ranks. Particularly in large groups and organizations, role differentiation on its own would not be sufficient to overcome disorder and chaos without an organizing structure to integrate inputs from these different roles. Indeed, organizational scholars have long proposed a number of problems associated with division of labor (Lawrence & Lorsch Reference Lawrence and Lorsch1967; March & Simon Reference March and Simon1958) that can potentially be addressed through differentiation in ranks. Although these problems can sometimes be overcome via solutions other than hierarchy (e.g., Heath & Staudenmayer Reference Heath and Staudenmayer2000), the current evidence points to rank differentiation as having considerable advantages in making sure that groups remain organized and effective, and that their members are satisfied and motivated to contribute to the group.