Has light reinforcing effects in humans and may contribute to the development of problematic usage of the internet and digital-based behavioral addictions?

This commentary complements the arguments by Tam et al. (2025) and offers a comprehensive approach when considering light conditioning in the context of the development and maintenance of problematic Internet use. Thereby, we illustrate the impact of light on humans also within the context of theoretical considerations and empirical studies. We agree with Tam et al. (2025) that there is a need for a better understanding of habit formation within addictive behaviors and we acknowledge the empirical challenges which are proposed in the article mentioned. At the same time, this commentary emphasizes that light should not be considered as an isolated reinforcer, but rather as a complementary component of other conditioned and cognitive tendencies (e.g., use expectancies), as well within the interplay of further processes in addiction research such as craving, attentional biases, and self-control abilities.