The more afraid a person is of a spider, the bigger that individual perceives the spider to be, new research suggests. In the context of a fear of spiders, this warped perception doesn't necessarily interfere with daily living. But for individuals who are afraid of needles, for example, the conviction that needles are larger than they really are could lead people who fear injections to avoid getting the health care they need. A better understanding of how a phobia affects the perception of feared objects can help clinicians design more effective treatments for people who seek to overcome their fears, according to the researchers.