A study by Knox & Inkster (1968) revealed something interesting about people at the racetrack. Just after placing a bet they were much more confident of their horses' chance of winning than immediately before the wager. What is intriguing is that nothing about the horses' chances had changed: it was the same horse, the same course, the same opposition.

What had changed was that the bettor considered his likelihood of winning had greatly improved with that ticket in hand.