How to get more truthful survey responses

How many sexual partners have you had?

Okay, I wouldn’t expect you to give that information to a stranger. But would you spill the tea if asked as part of a national medical research program? You might think you would – but evidence suggests otherwise.

The National Survey of Sexual Attitudes and Lifestyle (NATSAL) is conducted by UCL and the London School of Hygiene and Tropical Medicine. In 2010-12, the survey asked over 15,000 straight adults how many partners they had. Women reported an average of 8 partners; Men reported 12.

That is a logical impossibility. The numbers were obviously falsified.

You might assume that the participants simply stretched the truth because of the personal nature of the questions. And maybe that’s why they lied to a certain extent. But this survey is far from a unique example.

people lie. We are social animals and it is natural that we want to please our interlocutor.

A real problem for market researchers. Fortunately, behavioral science offers some excellent workarounds to get closer to the truth.

Commit to the truth

The first — and perhaps easiest — thing is to ask people to make a commitment to be honest before answering any questions. It’s a technique that the legal system relies on. And several studies suggest courts are on to something when they make witnesses swear to tell the truth.

One example is a 2002 study by Duke University’s Dan Ariely. For this experiment, participants were given a sheet of number puzzles and asked to solve as many as they could in a few minutes.

Ariely set up the study so that the papers were sometimes reviewed by a researcher. That meant there was no chance of cheating. In this setup, people solved an average of 3.3 puzzles.

A second group was allowed to self-report their score without supervision. The results in this group unsurprisingly increased to 5.55.

Eventually, Ariely recruited another group of people who also volunteered. But before reporting their graduation rate, they were reminded of their morals by agreeing to a statement that the degree falls under the university’s honors system.

Ariely noted that those who signed the pledge gave a score of just over three. In other words, the promise had kept them from lying — even when they thought they wouldn’t find out.

The study shows that people’s inclination towards truthfulness is fluid. It’s easy to nudge in the right direction. Simply including an early and prominent reminder of honesty in your surveys can increase truthfulness.

circle of trust

If you’re not convinced that a promise is enough, why not let your attendees know you’re going to review them?

Another technique psychology experimenters sometimes use to promote truthfulness is called “false pipeline.” Participants are told that they will be connected to a lie detector. The machine is not operational, but important, They believe it is so. And they tend to give honest answers.

Many studies prove this. In 1993, Neal Roese of Northwestern University conducted a meta-analysis of 31 studies using the fake pipeline. He found that the technique increased truthfulness significantly.

But it’s a pretty extreme setup. Not many respondents would agree to being hooked up to a polygraph.

The great thing about these experiments is that you don’t have to use them literally. Focus on the general principle. When people believe their answers will be checked for honesty, they will be more truthful. So when guiding your survey takers, emphasize that you plan to analyze the honesty of the responses. How you do this is entirely up to you – it doesn’t matter if this analysis is effective in detecting lies – the important thing is to let people know it’s going to happen.

What would others do?

A final way to get to the bottom of the truth is to ask participants how they think other people would behave. It seems we’re pretty good at judging the actions of others.

Evidence for this approach comes from a 2000 study by Nicholas Epley at the University of Chicago and David Dunning at Cornell University.

A few weeks before a daffodil charity sale, the researchers asked 251 college students to predict whether they would buy a flower. Participants were also asked to make the prediction for their peers.

83% of students said they would buy a flower. But they estimated that only 56% of their peers would.

Three days after the fundraiser, the researchers asked the group how many daffodils they actually bought. It turned out that only 43% had bought a flower. The students had greatly overestimated their own generosity. However, her predictions about the actions of others were closer to reality. They had still overestimated, but to a much lesser extent.

This suggests that you may get closer to the truth if you ask participants to comment on others rather than themselves. This may be due to our innate social nature – we want the “right” answer to be our own give behavior whether it is the truth or not. But we can be more honest with other people.

So the next time you interview customers — about sexual partners or otherwise — maybe start by squeezing out a commitment to truthfulness, let them know their answers will be analyzed, and consider asking them to answer on behalf of others.

Richard Shotton is founder of the consulting firm Astroten and author of The Choice Factory, a book on the application of behavioral science to advertising. He tweets to @rshotton.

Will Hanmer-Lloyd is chief strategy officer at Total Media.