According to a new research, the speed of your smile can shape the first impressions others have of you. Smiling too quickly can lead others to think that you are insincere, while slow grins appear more genuine.

A team of business advisors, as part of the research, examined how smiling can give clients a positive impression.

It was discovered by them that a smile, which appears too swiftly and does not extend to the eyes can sends signals that you lack sincerity.

People should avoid three types of grin, they further found.

The Enthusiast, a huge smile showing all of your teeth and wide eyes can be overbearing.

The Big Freeze, a constant, practiced smile that lacks sincerity.

The Robot, a tiny, polite smile, that doesn't display warmth.

The Sun quoted Lesley Meechan of the Glasgow-based Go Group as saying, "Studies show people perceive a slower, natural smile which floods the entire face to be more genuine."

"Smiling all the time appears over-pleasing and lowers your status," Psychologist Bridget Hanna added further. (With Inputs from Agencies)