"Someone who is perceived as attractive, due in part to physical traits, may be more likely to be perceived as kind or intelligent. The role of attractiveness in producing the halo effect has been illustrated through a number of studies."
An example of this is how tall men receive "gentle giant" while short men get "short man syndrome," despite the fact that this experiment shows short men are the least likely to be aggressive:
The University of Central Lancashire research for the BBC found taller men were more likely to lose their temper. Men of different heights duelled with wooden sticks but one of the subjects deliberately provoked the other by rapping them across the knuckles. Heart monitors revealed it was the taller men who flew off the handle more quickly and hit back.
After all, in this culture the ideal man is described as "tall, dark, and handsome."
I also once found out that virgin males are the least likely to commit crime (sources here and here). Despite this, we all know how undesirable men are often portrayed as creeps and predators. This is ignoring how most criminals are not virgins.
One of the interesting side effects I've noticed from the halo effect is that these groups tend to try extra hard to please, because they know they have a bad rep right off the bat. Unfortunately based on the stats I've posted, these groups are already more passive on average, yet it doesn't seem to be helping much. This is because society does not hate based on a fair ratio. A group with an unattractive trait could do less but they will be judged more harshly.
Undesirable groups should be taught they did nothing heinous characterwise, because, and I quote: ''Unattractive children who are unpopular may wrongly attribute their lack of popularity to some flaw in their character or personality,'' she says. Such an error, she believes, could result in lasting and painful scars. - Source
Others should be made aware of our human biases and preconceived notions. Can you believe many people don't even know what the halo effect even is? Once someone does, they may start catching themselves judging too quickly, even if it's after the fact.