Using temporally-lagged data from 146 business and engineering newcomers, we found evidence for a "positive side" of plasticity theory (Brockner, 1988, p. 547) in fostering newcomer adjustment. Specifically, as predicted, we found that higher newcomer generalized self-efficacy positively moderates the association between job design (i.e., task significance of the newcomer's job) and newcomer attitudes (in our study, organizational identification, job satisfaction, intentions to quit). Our findings promote plasticity theory as readily applicable to both newcomer adjustment and positive organizational scholarship. (Contains 3 figures and 2 tables.)