“…It is interesting that despite the benefits that shared goals produce, individuals do not always work efficiently or effectively in collective settings. Although group members' dissimilar values (e.g., innovativeness, decisiveness) and demographics (e.g., age, education) can explain much of the inefficiency of groups (Jehn, Chadwick, & Thatcher, 1997), group productivity or performance also tends to suffer because of motivational deficits that occur when people share a goal (Karau & Williams, 1993;Sheppard, 1993). In the present research, we accordingly examine the sources of individuals' motivation to contribute to shared goal striving.…”