The illusion of life is a magic trick. Used successfully, it can pull the wool over the eyes of an audience and fool them into believing that your character is alive and thinking. Building a consistant performance can sometimes mean the need for clear rules about who your character is or isn't. There may be a time when you have the funniest gag, but if used on a particular character, can break all believabity.
Over on the Temple of Seven Golden Camels, Mark Kennedy discusses this topic indepth, using examples from some of our favourite features including ''Rapunzel'' and ''Lady and the Tramp''.
Please click the pic to have a read!
Making this idea simplier, Jean-Denis Haas has created a nice post on Spungella about structuring the order of a character's thought process. Keeping his advice in mind may help build a more natural performance.
I wish to leave you with this great example from Team Fortress. Its a powerful introduction to a character. By remaining calm, smooth and collective while being attacked by surrounding gunmen presents the Engineer as much more deadly than his appearance portrays.
To watch, please click on the pic. Enjoy!