It is plausible to suggest that the effect size that we
found might be an underestimation of the true magnitude of the effect size for the relation
between moral development and recidivism, because none of the studies included
in this meta-analysis were specifically designed to examine the prediction of recidivism
from moral development. Besides, small effects are to be expected when predicting
multiple determined behaviors, such as delinquency, from a single predictor (Ahadi
& Diener, 1989)