A study in Body Acting

Body acting is not much different that animating a character..well, it is from a technical point of view, but the animator turns into an actor in the process of animating and should think as one. This skill teaches you on how to express your characters emotions throughout body language. Plus, you have the freedom to exaggerate your animation in a way you can not if you were an actor for instance.
Body acting is a non-verbal way of communication which is one of the most powerful elements that make a believable and dynamic animation. The movements of your character do not always need to be realistic in order to be believable. Here is an example of one very realistic animation :

This example is realistic and believable without any use of exaggeration, squash and stretch or slow in and slow out, but when we animate we also consider the 12 principles of animation. In the next example we can easily see the application of many of those principles which improve the animation and make it more dynamic:

As we can see there are a couple of moments which clearly show the use of squash and stretch, overlapping action and others. Pausing you character for a couple of frames makes a huge impact and brings out the way they are thinking aswell.