Scientists Explain The Reasons Behind The 'Halo Effect'

It's not a coincidence that many on-screen personalities, like news reporters, tend to be traditionally attractive. The common saying may be, "don't judge a book by its cover," but in terms of human psychology, that's exactly what we do thanks to the halo effect. The halo effect is a cognitive bias where we make assumptions about a person, product, or company based on an unrelated trait or traits. Scientifically, this result is known as generalized trust. It's one of many examples of heuristics, or mental shortcuts humans take to speed up information processing.

The name "halo effect" was first coined by the psychologist Edward L. Thorndike in 1920. In his initial research, he examined how military superiors evaluated 140 new trainees during training. The superiors rated the trainees on factors such as physique, intelligence, leadership, and personal character. Thorndike found that the overall ratings of each trait were correlated more strongly with each other than would be expected if each trait was evaluated alone. The initial impression the superiors had of the trainees — including their physical appearance — seemed to directly influence ratings such as intelligence.

Since Thorndike's initial research, scientists have studied the halo effect numerous times. Going back to the on-screen personality example, research consistently shows that humans rate good-looking people as more trustworthy. For a television news network, more viewers means more advertising revenue, so maintaining trust with their viewership can potentially help prevent viewers from tuning in elsewhere. This example of the halo effect isn't limited to the individual newscaster and may also extend to the network as a whole.

The halo effect influences how you see the world every day, whether you realize it or not. Thinking critically is expensive in terms of the energy output your body needs. Despite being relatively small, your brain uses about 20% of the calories your body consumes. In the same way that when your body feels tired after a long day, your brain also gets fatigued. You might take an elevator instead of the stairs to save physical energy. To save mental energy, you may rely on the halo effect to assume a product with nice packaging works better than one that is less eye-appealing

Heuristics like the halo effect are quick, subconscious mental shortcuts that speed up your decision-making and problem-solving. They allow you to get through the day without being paralyzed by every small choice you need to make. These shortcuts allow you to save mental energy, but they can lead to cognitive biases, contribute to stereotyping, or allow you to be manipulated. The partially explained cheerleader effect is another example of a common heuristic.

There's no shortage of ways the halo effect influences your daily life. Research suggests that colleagues generally perceive happy employees as being better at their jobs than unhappy employees. Humans seem to perceive clothing worn by models with attractive faces more favorably than clothing worn by less attractive models. No matter whether you think that AI is good or bad, AI virtual assistants that write in a more human-like way seem to lead to increased perceived trust. Inflated marketing claims on health supplements may make us assume some theoretical benefit when none has been proven.

Businesses often spend extravagant amounts of money on marketing campaigns to influence buying decisions. The halo effect is one phenomenon they rely on to influence customer perception. For example, they might show images of a happy family enjoying the product together to suggest their product brings families together.

In a 2021 study, researchers evaluated how eco-labels on food packages influence the perception of food products. The researchers found that adding official-looking labels to food products made consumers assume the products were more environmentally sustainable, of higher quality, and more expensive, even if the labels had no meaning. Consumers tended to infer environmental superiority and higher quality when examining products with both organic and non-organic certified labels.

The halo effect is a natural cognitive process that we all experience. You can't change how your brain is wired, but by understanding the effect, you can recognize when brands, people, or companies are using it to influence you. Like how understanding the psychology of Black Friday might prevent you from getting trampled, understanding the halo effect can also help you make more informed decisions about the world. Thanks to the halo effect, whether you like it or not, we're all literally judging books by their covers.