In our book, the end of chapter 9 talks about intelligent people being tricked. One of the biggest tricks of all times was the Cottingley Fairies Hoax. Although it happened almost a century ago, some people still believe it to be true. This hoax presents us on "what not to do" when evaluating pictures in terms of scientific thinking. In 1917, two cousins in England became very famous. Elsie Wright and Frances Griffiths took Elsie's father's camera and took pictures of both of them playing with "fairies".
People all over saw these pictures and actually believed that there were real fairies prancing around the girls. Though most people figured it out in the end, many people were stumped including the brilliant author of the Sherlock Holmes books, Sir Arthur Conan Doyle. Doyle even published a book in 1922, The Coming of Fairies, which was based on the Cottingley fairies. It was later found that the fairies looked exactly like illustrations found in a children's book, and therefore it was assumed that the girls cut the pictures out of the book. Both Frances and Elsie never admitted to this until much later in life. The Cottingley Fairies hoax is a prime example of people not using the six principles of scientific thinking, especially the principles of extraordinary claims, replicability, and Occam's razor.
When people evaluated the fairy photographs, they forgot to realize that they would need extraordinary evidence to back up this extraordinary claim of tiny fairies running around England. There was no evidence of fairies living. The girls could not prove that there were fairies either besides the photos they took. This leads into the next scientific principle of replicability. Elsie and Frances claimed that the fairies trusted them and would only come out for them and no one else. This means that no one other than the girls could have possibly seen the fairies and therefore could not confirm their existence. Finally, people should have automatically thought of a simpler explanation for these fairies (Occam's razor) however, most people didn't. They assumed that the fairies were real, not thinking that they could have been cut out from a book. I guess the book was right, "none of us is immune to making errors in thinking." I just can't believe people made the error of thinking that these fairies were real!