One idea critical to increasing a person's persuasiveness is the so-called "halo effect" — which doesn't receive as much attention as it should. When we judge others positively in one aspect of their lives, we often judge them positively in other unrelated aspects. This is known scientifically as exaggerated emotional coherence, and more commonly referred to simply as the halo effect.
Edward Thorndike first observed the halo effect in 1920 via a paper called "The Constant Error in Psychological Ratings," which analyzed military officer rankings of subordinates. If a soldier boasted a strong physical appearance, he also was considered to have impressive leadership abilities. If he were loyal, he also was rated as highly intelligent.
The correlations proved way too consistent for Thorndike, who determined that officers' impressions in one area of a soldier's experience too often colored their impressions in another.
That practice holds true today. If someone is attractive, he also usually is considered smart. If a person appears enthusiastic, she often also is perceived as hard working. Friendly? Must be a good leader, too. We draw generalized conclusions based on a specific data point.
Priming the halo pump
First is foremost. People's impressions are colored by the first piece of data they receive, and their subsequent impressions are shaped by that data. One of the earliest and most enduring studies of first impressions and the halo effect was completed by psychologist Solomon Asch, who asked people to evaluate the personalities of two individuals name Alan and Ben.
Alan: intelligent – industrious – impulsive – critical – stubborn – envious
Ben: envious – stubborn – critical – impulsive – industrious – intelligent
