What do you think of black cats? Are they unluckier than cats of other colors? Many people in Western countries think so. Scientists at the University of California, Berkeley (UC Berkeley), did a study on cat colours and people's understandings of cat personalities. The study found that people do judge  cat personalities by color. Scientists did a survey  on the Internet. There were 49 statements   matching five cat colorings with 10 personalities. People think orange and bi-coloured   cats are friendly, tri-coloured   cats are not generous, and white cats are calm, lazy and shy. As for black cats, people think they don't have special personalities. But why do so many people dislike keeping black cats as pets? People think black cats have less special personalities, which might be because of their bad reputation  . They think black cats may bring bad luck, especially at Halloween. Movies and television shows also make people believe that. Although people have these ideas, UC Berkeley scientists give another reason: people don't think black cats are pretty enough. After all, nothing can show black cats are unluckier than other cats. "You can't judge a cat by its colour, because it's the personality of the cat, not the colour, that will let you know if the cat is right for you," Cathy Marden, a scientist said. The passage mainly talks about   _  .
why black cats are popular in movies why people are not willing to keep black cats as pets different colour cats have different personalities different people have different ideas on black cats