Updated

Scientists Thursday unveiled a step-by-step guide to an age-old custom the average person performs 15,000 times during their life -- the handshake.

Researchers at the University of Manchester, in northern England, discovered that nearly one-in-five people questioned hated having to shake hands with the biggest complaints listed as sweaty palms, limp wrists, gripping too hard and lack of eye contact.

Professor Geoffrey Beattie, head of psychological sciences, devised the equation taking into account 12 key measures -- such as vigor, eye contact, hand temperature, positioning and length -- needed to convey respect and trust to the recipient.

He said: "The human handshake is one of the most crucial elements of impression formation and is used as a source of information for making a judgment about another person.

"A handshake reveals aspects of the personality of the person giving it -- for example, a soft handshake can indicate insecurity, whilst a quick-to-let-go handshake can suggest arrogance.”

Beattie’s guide to the perfect handshake applies to both men and women and reads: use the right hand; a complete grip and a firm squeeze (but not too strong); a cool and dry palm; approximately three shakes, with a medium level of vigor, held for no longer than two to three seconds.

The handshake must also be executed with eye contact kept throughout and a good natural smile with an appropriate verbal statement, according to the scientist.

The handshake has been a traditional greeting, a symbol of peace and a key part of business deals for thousands of years.

The formula: