“…These findings agree with existing evidence suggesting a role for 12-step involvement in recovery (Bond et al, 2003;Emrick et al, 1993;Humphreys et al, 1999;Kaskutas et al, 2002;McIntire, 2000;Tonigan, J.S., 2001;Tonigan, J. Scott et al, 2003;Tonigan, J.S. et al, 1996) and with evidence suggesting stronger relationships between better treatment outcomes and voluntary (vs. coerced) 12-step participation (Brandsma, Maultsby, & Welsh, 1980;Ditman, Crawford, Forgy, Moskowitz, & MacAndrew, 1967;Kownacki & Shadish, 1999;Walsh et al, 1991). The findings may also illustrate the well-established relationship between freedom of choice to perform a counterattitudinal behavior and attitude change toward that behavior (e.g., Brock, 1962;Brock & Buss, 1962;Holmes & Strickland, 1970).…”