Mannerisms are types of physical actions, reactions, and gestures that are customary and habitual in an individual. For instance, have you ever known a person that bites into a favorite food, smacks their lips and always says something like "Man, that's fine eating." This would be considered a mannerism. Mannerisms are basically habitual behaviors that a person has that has grown from their upbringing and environment. Mannerisms tend to be unique to each individual although sometimes family members can share common mannerisms.