The technique used by many of the drama schools involves the actor using their diaphragm (the area below your stomach) to fake crying and laughing. You basically pull the diaphragm in and out rapidly to stimulate your solar plexus to hopefully produce the desired result. It is also assumed that because the two emotions come from a similar physical area, the same approach can work for both.
There is another method acting school of thought.
In Method Acting, the actor is required to stimulate, for REAL, the appropriate emotion within themselves for the scene. The human being is a complex instrument and is capable of creating emotion at will – no need for faking.
The way that this is achieved is through the senses. We experience the world through our senses. We see things, we hear things, we touch, we smell and taste things. This is how emotion can be recreated.
For example, have you ever heard a song from your past that reminded you of someone or a particular moment, and started to feel emotional? Or, have you ever been really hungry, and started to salivate when thinking about your favourite meal? This is what Method Actors call ‘sense memory’.
Method Actors have acting classes and acting lessons on how to use their own memories in conjunction with their senses to recreate emotion, which they then fuse with the imaginary character and events they are portraying.
This is extremely effective for the actor in their actor training. It also allows a more interesting journey through their acting training. The actor works through a series of predefined exercises, and builds up a bank of memories which are then used when required.
In much the same way that a plumber or joiner selects the correct tool for a particular job, the Method Actor selects the appropriate memories for a particular scene.
Acting courses should be designed to empower the actor, and give them a way of working that is both creative and progressional. For the Method Actor, the more they experience in life, the more they have to bring to their acting. It is a continual process of improvement for the actor, and all actors should continually experiment in acting classes and acting courses.