subliminal

Subliminal refers to stimuli or messages presented below the threshold of conscious perception. In psychology, subliminal stimuli are detectable by the senses but not reliably identified or reported by the observer, yet they can influence thoughts, preferences, or behavior through unconscious processing. The term is often used for masked or flashed cues that are too brief or faint to be consciously detected.

The concept gained public attention in the 1950s after claims that subliminal advertising could steer consumer choices. A widely publicized study from 1957 reported that short messages shown during a film increased popcorn and cola sales; subsequent work failed to reproduce the effect, leading to widespread skepticism. Since then, researchers study subliminal processing mainly through laboratory methods such as masking and priming to examine perceptual thresholds and unconscious influence.

Evidence shows that subliminal or near-threshold stimuli can produce small, context-dependent priming effects under controlled conditions, but there is no robust evidence that subliminal messages reliably change complex behavior or produce lasting persuasion in real life. Methodological critiques highlight issues of detection, replication, and ecological validity. Ethically, subliminal messaging raises concerns about manipulation and consent, contributing to regulations banning subliminal advertising in several jurisdictions. In common usage, subliminal is often used more loosely to describe any influence thought to bypass conscious awareness, but scientific findings distinguish between laboratory-observed subliminal effects and broader claims often found in popular media. Related topics include subliminal priming and perceptual thresholds.