Here’s a bit of body-language trivia that you can have some fun with. Sometimes. OK, the opportunity probably won’t come up that often if you’re a student, but if you’re in business you’ll be able to ring it out every once in a while.
Here’s the trick: Just by looking at somebody you are able to tell whether he is right handed or left handed. This is only truly reliable when you encounter somebody who is wearing a suit jacket or sport coat, so it’s something you will mainly be able to use with men. But the secret is simple. Look at the wrinkles in the jacket’s sleeve, specifically those around the joint of the elbow. The sleeve of the dominant hand will be noticeably more wrinkled.
What you do with this information is up to you. I just casually say to the person, “you’re left handed, aren’t you?” This usually leads to a moment of surprise, then the confession, “yes, I am. How did you know?” At that point I lead the conversation toward the benefits of being observant and knowing about non-verbal clues.
This little trick is not going to start any new religions for you, but it is an fun, albeit occasional, way to start a conversation. And if nothing else, it’s another bit of useless knowledge that you can drop at parties to make yourself look smarter than you really are.