How the roll of a die can get people to tell the truth

Dice Help Scientists Get Honest Answers to Touchy Questions
[Via 80beats]

New tools for conservation?

What’s the News: Maybe it’s you—or maybe it’s the dice. A technique that relies on concealing individual transgressions while revealing greater truths is letting biologists get to the bottom of South African farmers’ killing of leopards.

What’s the Context:

In South Africa, there’s constant tension between carnivores and local farmers, who may kill animals they perceive as a threat to livestock. Knowing whether farmers are doing this helps conservationists understand the driving forces behind animals’ extinction and plot countermeasures, but since killing carnivores like leopards and brown hyenas is illegal, it’s hard to get a straight answer from farmers about their activities. Enter the randomized response technique, which was first developed in 1965. Also used by social scientists to get people to talk about their sex lives, it lets researchers see overall trends in taboo behavior without being able to pin a crime or an embarrassing behavior on any one person.


The subject rolls a die. If they roll a “1” they always answer the question “no”. If they roll a “6” they answer “yes”. No matter what the truth is.

Otherwise they are asked to answer truthfully.

This actually results in many people telling the truth than a standard survey. The ‘deniability’ of the dice throw means no one can point to them as an animal killer. But the overall stats allow the surveyors to tell what a populaton may be doing.

Kind of ingenious use of human foibles. People will more likely tell the truth if they can deny it.