If I were to tell you my friend Bill was often complimented on his rugged good looks and was often volunteering to raise money for the homeless, do you think he would be a good leader?
If you met Bill, you would more than likely make a brief assumption that due to his physical attractiveness characteristic and altruistic behaviour towards the homeless characteristic, that Bill is a great guy and would make a great leader. This would be the Halo effect in play. The Halo effect is when we make a positive generalisation about a person based on specific characteristics. Bill, who is imaginary, hasn’t given enough information to us to make an accurate evaluation of his leadership qualities. We have focused in on some of the good characteristics of Bill and then decided ourselves that there would be a causal relationship between those characteristics and the characteristics of a good leader.
This is a common error that we all make. Palmer & Peterson (2012) found that political candidates perceived as attractive individuals are subjectively viewed as more knowledgeable even after objectively accounting for their levels of factual knowledge.
In another study by Ostrove & Signall (1975), participants were asked to sentence criminals based on their photos and crimes. Participants would assign more lenient sentences to the attractive defendant than to the unattractive defendant; when the offence was attractiveness-related (swindle), the attractive defendant would receive harsher treatment. Results confirmed a cognitive explanation for the relationship between the physical attractiveness of defendants and the nature of the judgments made against them.
The Halo effect can obviously be a bias that gets us into trouble. Correlation does not equal causation and when making a decision we have to be mindful to weigh up the facts as they relate to that specific characteristic which we are judging.
Palmer, CL; Peterson, RD (2012), "Beauty and the Pollster: The Impact of Halo Effects on Perceptions of Political Knowledge and Sophistication
Ostrove, Nancy; Sigall, Harold (1975). "Beautiful but Dangerous: Effects of Offender Attractiveness and Nature of the Crime on Juridic Judgment". Journal of Personality and Social Psychology. 31 (3): 410–14. doi:10.1037/h0076472.