“…For some (e.g., Braver, in press; Kerr, in press; Ostrom, Walker, & Gardner, 1992), the evidence supporting the commitment explanation seems stronger. First, both theory (e.g., Janis & Mann, 1977; Leventhal, 1976) and data (e.g., Stults & Messé, 1985; Tedeschi, Lindskold, Horai, & Gahagan, 1969; Tedeschi, Powell, Lindskold, Gahagan, 1969) attest to the existence of a commitment norm that prescribes that one should carry out those actions one has promised or committed onself to perform. This norm is closely related to the expectation that one's beliefs and actions be consistent (Cialdini, 1984).…”