Several questions remain unanswered to date: What type of forgiveness intervention is more effective, individual or group treatment, psychotherapeutic or psychoeducational approach, long-term or brief treatment, and under what circumstances and with what populations? What participant, contextual, and intervention process variables affect the forgiving process? This meta-analysis has attempted to answer some of these questions. The statement of the null hypothesis was as follows: Forgiveness intervention for adults, delivered via individual treatment, will be equal in effectiveness to forgiveness intervention, delivered in group treatment, as defined by statistically and clinically significant and meaningful effect sizes.
Based on a comprehensive review of the forgiveness literature, four hypotheses were formulated: Hypothesis 1: Participants receiving forgiveness intervention, delivered via individual treatment, will not demonstrate equal forgiveness improvement as compared to forgiveness intervention, delivered in group treatment, as defined by clinically and statistically significant effect sizes and meaningful differences. Hypothesis 2: Participants receiving longer duration (6 or more hours) forgiveness intervention will demonstrate greater improved forgiveness than participants receiving shorter duration (less than 6 hours) forgiveness intervention, as defined by clinically and statistically significant effect sizes and meaningful differences. Hypothesis 3: Participants, with severe offenses, receiving forgiveness intervention will demonstrate greater improvement in forgiveness than participants, with less severe offenses, receiving forgiveness intervention, as defined by clinically and statistically significant effect sizes and meaningful differences. Hypothesis 4: Participants receiving forgiveness intervention, in which the sample consists of 100% females, will demonstrate greater forgiveness improvement than participants receiving forgiveness intervention, in which the sample consists of less than 100% females, as defined by clinically and statistically significant effect sizes and meaningful differences.
The first hypothesis was confirmed. The combined forgiveness effect for individual treatments was a clinically and statistically significant large ES of 1.409, 95% CI: 0.664–2.154. For group treatments, the combined effect was a clinically and statistically significant, but small, ES of 0.296, 95% CI: 0.124–.468. The null was rejected.
In support of the second hypothesis, long-term treatment duration (6 or more hours) showed a significant, moderate to large ES of 0.711, 95% CI: 0.433 - 0.990. Whereas, brief treatments (less than 6 hours) demonstrated a small nonsignificant combined ES of 0.064, 95% CI: -0.089–0.216. The meta-regression of duration of treatment (hours) for all 26 subgroups demonstrated a significant relationship of hours of intervention with forgiveness effect.
Corroborating the third hypothesis, interventions in which participants experienced more severe offenses, demonstrated clinically and statistically significant larger forgiveness effect, ES 0.958, 95% CI: 0.609 – 1.308 than treatments in which the participants had experienced less severe offenses, which demonstrated a nonsignificant ES of 0.075, 95% CI: -0.053 – 0.203.
The fourth hypothesis was also supported. The combined effect for all treatments with 100% female participants demonstrated a large clinically and statistically significant effect size, ES 1.284, 95% CI: 0.903–1.666 (These same interventions were led by 100% female leaders). Interventions with less than 100% female participants had a small to medium statistically significant forgiveness effect of 0.273, 95% CI: 0.055–0.491.
The meta-analysis tentatively suggested other variables that moderate improvement in forgiveness. A psychotherapeutic model, used in individual and group treatment, showed a significant large effect size, ES 1.337, 95% CI: 0.898 - 1.777; the psychoeducational-experiential models, were used in secular and faith-based treatments group treatments. They demonstrated a significant medium combined effect size, ES 0.541, 95% CI: 0.211–0.872. Faith-based group treatments (psychoeducational models, with and without experiential elements) demonstrated a large significant ES of 0.789, 95% CI: 0.145–1.433.
Interventions with 52% or more European Americans demonstrated a significant moderate to large ES of 0.668, 95% CI: 0.369–0.966; however, for all subgroups consisting of 51% or less European Americans, the demonstrated effect was small and nonsignificant, ES 0.045, 95% CI: -0.098 to 0.188. For religious affiliation (which was reported in only 12 of the 26 treatments), Christian denominations demonstrated a clinically and statistically significant moderate to large forgiveness effect, ES 0.629, 95% CI: 0.364–0.893.
The following leader characteristics were analyzed: leaders not blind to the hypothesis demonstrated a significant medium effect, ES 0.504, 95% CI: 0.228–0.780; leaders with more than 8 hours of training on the model showed a clinically and statistically significant large effect, ES 0.840, 95% CI: 0.361–1.319; and leaders with 4 or more years of experience demonstrated a large significant forgiveness effect, ES 0.658, 95% CI: 0.313–1.002.
Overall findings suggested forgiveness intervention (individual and group treatment) is beneficial to clients. Improvement in forgiveness was significantly moderated by specific participant, contextual, and process variables. Individual forgiveness treatment intervention was supported as more effective, than group treatment forgiveness. The null hypothesis was rejected and all 4 hypotheses were supported. (Abstract shortened by UMI.)