An experiment showed that people often lie about the result of a secret die roll if it benefits them.
The takeaway for board game designers, according to BoardGameNews:
“If you want someone to be honest, then do not allow him to roll a die in secret.”
http://boardgamegeek.com/blogpost/9382/links-flash-mob-game-reviews-the-hasty-cheater-ye
RELATED:
Preventing cheating: Is the honor system sufficient?
http://cardboardedison.tumblr.com/post/19570523236/preventing-cheating-is-the-honor-system