Originally published July 9, 2017
Everybody lies. People lie about how many drinks they had on the way home. They lie about how often they go to the gym, how much those new shoes cost, whether they read that book. They call in sick when they’re not. They say they’ll be in touch when they won’t. They say it’s not about you when it is. They say they love you when they don’t. They say they’re happy while in the dumps. They say they like women when they really like men. People lie to friends. They lie to bosses. They lie to kids. They lie to parents. They lie to doctors. They lie to husbands. They lie to wives. They lie to themselves. And they damn sure lie to surveys. Here’s my brief survey for you:
Have you ever cheated in an exam?
Have you ever fantasised about killing someone?
Were you tempted to lie?
Many people underreport embarrassing behaviours and thoughts on surveys. They want to look good, even though most surveys are anonymous. This is called social desirability bias. An important paper in 1950 provided powerful evidence of how surveys can fall victim to such bias. Researchers collected data, from official sources, on the residents of Denver: what percentage of them voted, gave to charity, and owned a library card. They then surveyed the residents to see if the percentages would match. The results were, at the time, shocking. What the residents reported to the surveys was very different from the data the researchers had gathered. Even though nobody gave their names, people, in large numbers, exaggerated their voter registration status, voting behaviour, and charitable giving.
The article is here.