People are walking around with books on the end of their arms describing how their mind, body and heart work, themes in their life, strengths, weaknesses and other aspects of their constitution and biography. As you learn the language of the hand, as expressed through structure and movement, more and more is revealed, and even at a distance it can be informative. There is a branch of palmistry developed in Medieval Europe, for example, based on reading the hands of lords and ladies as they waved from their carriages, mapping the shape of the phalanges between the knuckles to the interests of the dignitaries. Basic skills in reading gesture and major lines can help you decide how and when to approach someone you don't know.