This study explores how altruistic motivation, social behavior, well-being, and nature relatedness influence pro-environmental behavior on Instagram, integrating the Norm Activation Model (NAM) and the Theory of Planned Behavior (TPB). Sharing nature-related content fosters eco-friendly actions, climate change awareness, and well-being. This study applies NAM and TPB to understand these motivations and inform social media interventions. A cross-sectional survey of 852 Instagram users (18+) was conducted to measure key variables. Instagram engagement was assessed with the Instagram Intensity Scale (Ellison et al., 2007) and Social Networking Time Use Scale (Olufadi, 2016), while Nature Relatedness was measured using the Nature Relatedness Scale (Nisbet et al., 2009). The Environmentally Friendly Information-Sharing Behavior was evaluated by Chen’s (2020) scale. Well-being was conceptualized as a multidimensional construct and assessed using the Well-Being Index (Bech, 2004). Hypotheses were tested through hierarchical regression and correlation analysis. Intensity of Instagram use positively correlates with Nature Relatedness (r = 0.29, p < 0.001), reinforcing ecological consciousness. Nature Relatedness is strongly associated with Environmentally Friendly Information-Sharing Behavior (r = 0.40, p < 0.001), highlighting Instagram’s role in digital environmental advocacy. Nature Relatedness is also strongly associated with Well-Being (r = 0.64, p < 0.001), demonstrating psychological benefits beyond self-esteem, supporting NAM and TPB. Nature Relatedness is key to fostering pro-environmental behavior and enhancing Well-Being through Instagram. Findings suggest leveraging Instagram’s nature-related content to promote Eco-Friendly Behavior and Well-Being, guided by NAM, TPB, and Nature Relatedness.
