MUCH has been written about the "beauty bias," the hiring preference for people who are perceived as good-looking.

Many hands have been wrung over the possible danger of violating anti-discrimination laws by looking at applicants' pictures before hiring.

Nick Salter, an assistant psychology professor, was aware of all that but wanted to probe further, given that LinkedIn profiles have become the premier way for hirers to scope out job candidates.

His questions: Is it better for applicants to post their pictures on LinkedIn, even if they wouldn't be considered attractive? Or is it better to omit your picture from your profile?

In a controlled experiment that offered identical professional profiles, except for the pictures, Salter found preferences to see a face, any face.

"People just want to look at you," he said. "The findings of an attractive preference weren't surprising. What I wasn't sure I'd find was that having no picture was worse than having an unattractive picture.

"A picture makes you more of a person and less of just a piece of paper."

Salter said his sample reviewers also gave higher ratings to candidates who had good-quality photos. Fuzzy snapshots reduced reviewers' impressions.

Salter's findings were distributed by the Society for Industrial and Organizational Psychology.

His experiment used only photos of women of about the same age in order to avoid gender and age biases. Race didn't alter his results.

Salter acknowledged that his findings might differ about the value placed on looks if the samples were male or of different ages. But he thinks the value of including a photo would remain constant.

"I can see how people worried about age bias might not want to put in a picture, but people think you may be trying to hide something or that you didn't take the time and effort to add a picture, or that you're not technologically savvy."

Diane Stafford is the workplace and careers columnist at The Kansas City Star.