Have you ever ignored something until another person showed interest in it? Maybe you were looking at a particular dress without feeling strongly about buying it. Then your friend said, "I actually really like that one." Suddenly, you wanted it. Or perhaps you had no interest in a restaurant, holiday destination or even a particular job until someone else started talking excitedly about it.
Psychology suggests this surprisingly common reaction can be explained by social comparison, envy, perceived value, scarcity and psychological reactance.
