People have always said yawns are contagious, but who knew that there was actually something called contagious behavior! Contagious behavior is defined as a more or less instinctive or reflexive behavior triggered by an occurrence of the same behavior in another individual. The first example in the text was yawning. (pg 459) Contagious behavior is apparent in humans and also in some animals. Fear is another thing that is ‘contagious.’ Ducks are another example, when a flock of ducks are together and one duck flies off, all the other ducks follow, even if there is not potential danger. Laughing can also be seen under contagious behavior. People usually do not laugh all that much when they are alone for example watching a funny movie, but when with a group or crowd of people laughing is contagious. Television programs know this and that is why there are laughing tracks or live audiences laughing in comedy shows.