This Ted talks about how your body language could affect how people think of you, and the way they interpret the way you communicate to them through your palm gesture. if you talked and kept your palms facing upwards that means you aren't that serious and you might look a bit silly but the person would go with what you are saying since the idea you are suggesting might be or looks fun. Now if your palms were facing downwards this would indicate that you are giving orders and people might take this rudely and not follow with what you are saying. now the last gesture is pointing this means the person have no choice and this is a directive.

However this doesn't work in all situation there are situation where you have to use a certain gesture. imagine this if the fire alarm goes off and you want to give instructions on what to do with a palm upward gesture people wont follow your instructions and everyone would panic, but if you used a commanding gesture they would feel calm and follow your instructions. This is the example of the power of body language if used correctly you can persuade people , and keep in mind this is with only your hands.