On some forms, the signature was required at the top, and on others, it was asked for at the bottom. And what do you know: On average, people who were made to sign their names at the top reported lower math scores and also filed for fewer reimbursements. Unless those people just happened to be dumber and more forgetful, this means that signing at the top makes you more honest.
But why would that happen? This is actually the result of a psychological phenomenon called the signature effect -- when we write down our names, we are subconsciously reminded of who we are and what we aspire to be. And whether you believe it or not, most people aspire to be good, and good guys don't generally lie.
"Unless it's about condoms -- then it's time for the candy wrapper gambit."
So when we write our signatures before we are forced to decide if we'll lie or not, we're subconsciously throttling that tiny devil inside of us that makes us do bad things. On the other hand, when we write it at the bottom after filling out the form, the effect is made redundant, since we've already lied our asses off.