To pay or not to pay ? : Do extrinsic incentives alter the Köhler group motivation gain ?

The Köhler effect is an increase in task motivation that occurs in performance groups when one is (a) less capable than one’s fellow group members, and (b) one’s efforts are particularly indispensible for group success. Recently, it has been shown that the Köhler effect can dramatically increase one’s motivation to exercise. The present study examines the potential moderating effect of the provision of extrinsic incentives on such Köhler motivation gains. When participants were offered such an extrinsic incentive for persisting at an exercise task, a robust Köhler effect was observed—participants who thought they were the less capable member of a dyad working at a conjunctive group exercise task persisted 26% longer than comparable individual exercisers. But an even stronger effect (a 43% improvement) was observed when no such incentive was on offer. Possible explanations and boundary conditions for this moderating effect are discussed. Incentives and the Köhler Group Motivation Gain Page 3 To Pay or Not to Pay? : Do Extrinsic Incentives Alter the Köhler Group Motivation Gain? In the United States, and to lesser extents in other developed countries, obesity is a serious problem, contributing to a number of poor health outcomes, including diabetes and heart disease (e.g., CDC, 2010: Weinstein et al., 2004). Although obesity is a complex phenomenon, with several genetic, dietary, medical, and lifestyle factors playing significant causal roles, insufficient physical activity appears to be a major contributor (USDHHS, 2008). Low demands for physical activity in normal daily routines mean that for many, achieving enough physical activity for basic fitness requires that their normal routines must be supplemented in some way (e.g., through an exercise regimen or participation in sport). Most people recognize the value of exercise and many try to initiate one or another exercise program. However, it is notoriously hard to persist in keeping such good resolutions—e.g., research has typically reported about a 50% drop out rate within the first 6 months of initiating an exercise program (Dishman, 1994). Thus, a key question in any attempt to improve fitness and combat obesity is, “how can motivation to exercise be enhanced? ” We suggest that one general answer to this question is, “create the right social context for exercise. ” There are a number of social factors that have been shown to influence motivation to exercise (Franzini et al., 2009; USDHHS, 2008). These include social support from health professionals, family, and friends (Coleman, Cox, & Roker, 2008; Zakarian, Hovell, Hofstetter, Sallis, & Keating, 1994), social modeling of physical activity (Feltz & Riessinger, 1990; Fox, Rejeski, & Gauvin, 2000), having fellow exercise participants (Carron, Hausenblas, & Mack, 1996), and group exercise programs (Dishman & Buckworth, 1996). A novel but promising approach is to exploit social psychological processes that have been shown to enhance motivation in task performing groups (e.g., for overviews, see Baron & Kerr, 2003; Karau & Williams, 1993). In particular, considerable research over the last 35 years has shown that working together with others at a task can have powerful effects on task motivation. Much of the earliest research showed that certain group work conditions could be Incentives and the Köhler Group Motivation Gain Page 4 demotivating, producing group motivation losses (Steiner, 1972)—e.g., when being in the group meant that individual levels of effort were harder to identify or monitor (e.g., Harkins & Jackson, 1985; Williams et al., 1981), when group members thought that they might be able to free ride on the efforts of other members (e.g., Kerr & Bruun, 1983), or when group members thought that others might not be doing their fair share and reduced their own efforts to avoid being exploited (e.g., Kerr, 1983). But more recent work (e.g., Erev, Bornstein, & Gallili, 1993; Williams & Karau, 1991) has shown that there are also certain group work conditions that can lead group members to work harder than they would work if working individually, producing group motivation gains. The most thoroughly studied and documented of these phenomena is the Köhler effect (Köhler, 1927). The Köhler effect occurs when low ability group members increase their motivation (a) due to an invidious social comparison with their more capable group members and/or (b) when low ability group members see their contributions as particularly indispensible for group success and social evaluation (Kerr et al., 2007). Many factors that moderate this effect have also been identified (e.g., the discrepancy in member abilities, Messé et al., 2002; group sex composition, Lount et al., 2000; how long the group has worked together; Lount et al., 2008). Most importantly, the demands of the group task can be crucial; group tasks that make the least capable member’s performance critical for group success (e.g., a mountain climbing team tethered together and able to climb at the speed of the slowest climber--what Steiner, 1972, called a conjunctive group task) generally results in the strongest Köhler effect (Hertel et al., 2008; Kerr et al., 2007). See Weber & Hertel (2008) for a meta-analytic or Kerr & Hertel (2011) for a narrative review of this