Emotional salience makes information feel important before it has proved that it is important.
Human attention is limited, so the mind needs ways to select what deserves processing. Emotional salience is one of those selection forces. Threat, excitement, outrage, novelty, and personal relevance can make a stimulus stand out from its surroundings and receive disproportionate attention.
The danger begins when prominence is mistaken for significance. An alarming headline may be more emotionally salient than a slow-moving structural fact without being more truthful, more probable, or more relevant to a person’s long-term interests. Salience changes the order in which information is encountered. That changes what is remembered, discussed, and acted upon.
This makes emotional salience useful to anyone competing for attention. Advertising, news, social media, and financial commentary can construct messages around emotional intensity because intensity keeps the audience looking. The information does not need to contain more substance. It only needs to produce a stronger response than the surrounding material.
Emotional salience is not the same as irrationality. Emotion can identify genuine danger or meaning. The error is allowing the feeling of importance to substitute for examination. Emotion can move judgment, and manipulation begins when that movement is engineered while the target is denied the chance to recognise what is happening.
Source: Reference synthesis: the overview of salience in perception and cognition, including the APA salience hypothesis and related work on vividness and availability. The source is explanatory rather than a peer-reviewed primary study.