characteristics combine in a linear fashion such that the mean or sum of individual characteristics
represents the team-level construct (Chan, 1998). The extent of behaviors may vary among
individuals, but individual contributions are all weighted equally. This has also been labeled
amplitude (or numerical action) and is operationalized as the mean of all individual team member
scores (Barrick et al., 1998; Senior, 1997). This additive understanding does not privilege the work of
a particular individual or categories of persons, nor is there a presumption about which individual
behavior carries more weight. This multiple sense is the most common understanding invoked in the
growing number of references to shared leadership in the literature (Gronn, 2002) and is the way
shared leadership is considered in the study described in this chapter.
9.3 TEAM EFFECTIVENESS................................................................................................................................................
The relationship between shared leadership and team effectiveness has been the subject of a few
studies in the past decades. These empirical studies have provided support both for the feasibility of
shared leadership and for the significance of its influence on team performance above and beyond the
influence RIWKHWHDP¶VKLHUDUFKLFDOOHDGHU(Barry, 1991; Bowers & Seashore, 1966; Carson et al.,
2007; Pearce & Sims, 2002). The supposition tested in this study is that:
H: Shared leadership adds significant explanatory value for team effectiveness (above and beyond the
impact of the vertical team leader).
³Performance is the most widely studied criterion variable in the organizational behavior and human
UHVRXUFH PDQDJHPHQW OLWHUDWXUHV ́(Bommer et al., 1995, p.587). Interestingly, team research has
focused on the who is part of the team, and how team members cooperate. Teams studies have
resulted in ³DILQH-grained analysis of internal group dynamLFV>«@ZLWKJURXSVSULPDULO\DVFORVHG
V\VWHPV ́(Ancona, 1990, p.335). The focus has been largely on the interaction among group members
(Gladstein, 1984). Team performance has been ³OHVVV\VWHPDWLFDOO\DGGUHVVHG ́(Ilgen, 1999, p.131).
As a consequence we know a lot about the antecedents and mediating influences of team behavior and
much less on what comes out of it.
Team research has recently started to take organizational outcomes into account. In particular with
reference to Top Management Teams (TMTs), team characteristics were aligned with organizational
outcomes. Alvarez and Svejenova (2005) for instance, examined shared leadership with top-level
leaders. They found that organizations face competing demands, on the one hand aligning closely with
the environment (similar to Client centricity in the strategic leadership model), and on the other hand