Definition
Sensory priming is the unconscious shaping of behavior by recent sensory input. A sight, sound, smell, or even a temperature registered moments earlier can tilt a decision made afterward — without the person ever noticing the cue or crediting it with any influence.
In Behave, sensory priming appears in the topic on the seconds and minutes before a behavior. It is one of Sapolsky's sharpest demonstrations that the self we experience as a free chooser is constantly nudged by inputs below the threshold of awareness.
Why it matters
How it works
A recent sensory cue activates a web of associations in the brain — concepts, emotions, motor tendencies linked to that cue. Because activation lingers, those associations remain slightly more accessible and pull subsequent judgment toward them. Holding something warm can make people rate a stranger as warmer; a faint unpleasant smell can make moral judgments harsher; a subliminal angry face can sharpen a threat response.
The effect runs partly through fast emotional circuitry, including the amygdala, which reacts to charged cues before conscious processing finishes. Sapolsky is careful about the scale of these effects: priming bends behavior, it does not dictate it. But the lesson holds — context reaches into the brain through the senses, continuously and invisibly.