Going green for Eco or Ego? A meta-analysis of the comparative effects of environmental appeals and personal appeals on pro-environmental outcomes

Informational appeals often draw on environmental or personal reasons to elicit sustainable behavioral change. Research on this topic has flourished in the past decade, yet there is no consensus regarding which appeal performs best and when one outperforms another. To this end, we conducted a meta-analytic review to compare the effectiveness of environmental and personal appeals in promoting pro-environmental outcomes based on 215 effect sizes extracted from 194 independent samples across 101 articles. Our findings showed that both environmental and personal appeals effectively stimulated pro-environmental outcomes, with environmental appeals holding a small advantage over personal appeals in encouraging pro-environmental intentions (but not actual behaviors). Moderator analyses showed that (a) the comparative advantage of environmental over personal appeals, especially monetary appeals, was more pronounced in studies measuring intentions than those measuring behaviors; and (b) in more individualistic countries, the comparative effects of environmental appeals were weaker against monetary appeals. Furthermore, combined appeals were as effective as environmental appeals alone but more effective than personal appeals. These findings provide avenues and directions for future research, as well as practical implications for developing effective pro-environmental messaging interventions.