"Undoubtedly, there was an evolutionary advantage to fast judgments about whom to trust, to follow, to challenge, and so on. In today’s world of business, though, such snap judgments aren’t always a good thing. Choosing a vendor, a political candidate, or a job applicant based on a 100 millisecond impression may not always yield the best results."

Numerous studies have been conducted on faces and first impressions, using both photos of real people and computer-generated faces. It was a 2006 study by Janine Willis and Alexander Todorov at Princeton that established the power of those first 100 milliseconds.

Read this entire article by Roger Dooley on Forbes.com.