Hesitation. People display hesitancy in several different ways. If someone keeps their hands in their pockets, there could be a slew of reasons for their hesitancy. Perhaps they are a germaphobe or perhaps they do not have what is seen as a strong handshake. Either way, a hesitant person may keep their hands in their pockets.
Dishonesty. Many people feel that someone who only speaks with their hands in their pockets may be dishonest or untrustworthy. This may be the case for some people, but it may not be true for all people. Untrustworthy people do not gesture as often as most people do, so hiding hands in pockets is seen as being abnormal and withholding.
Women. Unfortunately, the primary focus on people with their hands in the pockets is on me for two reasons. The first reason is that women are vastly more concerned with body language and reading nuance than men. The second reason is that fashion has failed superbly when it comes to women’s clothing having pockets.