Because Scarlett Johansson is attractive, people are biased to think she's a good person. AP If you want to get paid, it helps being beautiful.

Sean Salter, a finance professor at Middle Tennessee State University, found as much in a 2012 paper on real estate brokers.

The more attractive the broker, the higher their wage.

It has to do with a bias toward beauty that we all unconsciously have.

"Let's say you're driving down the road and you see the agent on the billboard, and it's an attractive picture," Salter told US News.

"Your first impression is that this is an attractive person," he said. "So before you even hire this person to sell your home, you already have a positive impression of that person in your mind."

Psychologists call this pattern the halo effect, where you take one aspect of somebody — like their physical attractiveness — as a proxy for their overall character.

First coined back in 1920, the halo effect describes how our impression of a person forms a halo around our conception of their character. The better someone looks, the better a person we think they are.

The halo effect shapes our professional lives in loads of unnerving ways.

Research shows that fields with a lot of face-to-face interactions, like law or politics, put the most emphasis on your looks.

And good-looking people are paid a premium. Daniel Hamermesh, a University of Texas psychologist who studies beauty in the workplace, has found that a person with above-average looks earning $20 an hour over a 40-year career would earn $1.69 million, while a person with below-average looks would pull in $1.46 million.

In one sample of Americans and Canadians, economists found that attractive people make 12% to 14% more money than unattractive people. A study of simulated job applications found that good grooming did more to increase the chance of getting hired than job qualifications.

University of Michigan information science professor Markus M. Mobius has identified three reasons why beautiful people are more successful:

1. Physically attractive workers are more confident, and higher confidence increases wages. 2. For a given level of confidence, physically attractive workers are (wrongly) considered more able by employers. 3. Controlling for worker confidence, physically attractive workers have better verbal skills (such as communication and social skills) that raise their wages when they interact with employers.

While it might be impolite to think about it, looking good — or at least taking care of your appearance — is a professional skill, one that headhunters look for.

For Hamermesh, appearance can't be ignored.

"Like any other skill that you don't have, if you're bad-looking, avoid the occupations where it matters," he says.