Scientists at the University of Manchester have come up with a mathematical formula which takes into account 12 aspects of a hand-shake including vigour, eye contact, hand temperature and positioning.  This is it:

PH = √ (e2 + ve2)(d2) + (cg + dr)2 + π{(4<s>2)(4<p>2)}2 + (vi + t + te)2 + {(4<c>2 )(4<du>2)}2

(e) is eye contact (1=none; 5=direct) 5; (ve) is verbal greeting (1=totally inappropriate; 5=totally appropriate) 5; (d) is Duchenne smile – smiling in eyes and mouth, plus symmetry on both sides of face, and slower offset (1=totally non-Duchenne smile (false smile); 5=totally Duchenne) 5; (cg) completeness of grip (1=very incomplete; 5=full) 5; (dr) is dryness of hand (1=damp; 5=dry) 4; (s) is strength (1= weak; 5=strong) 3; (p) is position of hand (1=back towards own body; 5=other person’s bodily zone) 3; (vi) is vigour (1=too low/too high; 5=mid) 3; (t) is temperature of hands (1=too cold/too hot; 5=mid) 3; (te) is texture of hands (5=mid; 1=too rough/too smooth) 3; (c) is control (1=low; 5=high) 3; (du) is duration (1= brief; 5=long) 3.

For those of you that can’t build rockets, here’s the layman’s version:

The rules for men and women are the same: right hand, a complete grip and a firm squeeze (but not too strong) in a mid-point position between yourself and the other person, a cool and dry palm, approximately three shakes, with a medium level of vigour, held for no longer than two to three seconds, with eye contact kept throughout and a good natural smile with a slow offset with, of course, an appropriate accompanying verbal statement, make up the basic constituent parts for the perfect handshake.