Testing a WOOP-SET intervention to promote loneliness-prevention intentions and examine ageism among middle-aged Japanese regular employees

Population aging has heightened the need for interventions that prepare middle-aged adults for social connectedness after retirement while addressing ageism. This study examined a brief online WOOP-SET intervention that combined Wish, Outcome, Obstacle, and Plan (WOOP) exercises for loneliness prevention with a Stereotype Embodiment Theory (SET)-based message emphasizing continuity between the present self and the future older self. Two online studies were conducted with middle-aged Japanese regular employees aged 40–64 years. Study 1 used a single-group pre-post design ( N = 200) and showed pre-to-post increases in behavioral intentions to engage in loneliness-prevention actions and decreases in ageism following the intervention. Study 2 used a larger quasi-randomized controlled design ( N = 759) comparing the WOOP-SET intervention with an unrelated control task. Participants in the intervention condition showed a significantly greater increase in self-reported loneliness-prevention intentions than those in the control condition, whereas no significant between-condition effect on ageism was observed. These findings suggest that the combined WOOP-SET intervention may increase immediate preparatory intentions concerning post-retirement social connectedness, whereas its effect on ageism remains uncertain.