Cialdini asked his subjects to read a short biography of Grigori Rasputin, the notorious monk who served as an adviser in the court of Czar Nicolas II, and to give their opinion of him. The biography depicted Rasputin as a mendacioius and manipulative villain. In half the cases Cialdini had adjusted Rasputin’s birthday so that it matched that of the reader. Those subjects who shared a birthday with Rasputin were ovrewhelmingly more likely to rate him positively — as a strong and effective leader with many redeeming qualities.
That is from Jake Halpern’s Fame Junkies: The Hidden Truths Behind America’s Favorite Addiction. By the way, Bob Cialdini’s Influence is one of my all-time favorite books, if you don’t already know it you should.