The Psycho-Social Influence of Lighting in Space Perception An Experimental Proof of Concept

Lighting design is one of the interior architectural elements that can influence human psychology and behaviors. According to cognitive-affective psychology, light influences the brain by sending visual messages through the perceptual pathway, which may influence people in affective, cognitive, associative, and motivational ways. The lit spatial envelope can send social-affective, cognitive, and behavioral messages, hence driving social behaviors. This article reports an experimental proof of concept that tested four alternative lighting conditions with twenty participants in couples. The experimental subjective assessment was performed through the administration of questionnaires and the observation of real behaviors. The analysis of results aims to present how certain lighting parameters affect the subjective psycho-social responses in terms of environmental atmosphere perception, lighting appearance, social appraisal and impression, prospect evaluation, and sociability. In particular, results showed that the dim warm white lighting enables relaxing atmospheres and more favorable impressions for socialization. This lighting condition contributed to longer conversations. A direct/indirect lighting defined more positive and sociable atmospheres, giving the participants a higher prospect and a sense of cohesiveness. It allowed watching the other person’s state and eyes as well as the surroundings, thus influencing interpersonal distance. A more open postural attitude between participants was found in the warm dim direct/indirect lighting setting. The study emphasizes the necessity of appropriate lighting strategies to support the design of the social dimension in environments where collaboration and socialization are essential for overall quality of life. Limitations and further applications are discussed.