The Presumptive Is a Powerful Truth Serum

Uncovering the unknown by supposing you know.

Posted Nov 18, 2018

J. R. Bale/123RF
Source: J. R. Bale/123RF

The presumptive is a statement or question that gives the illusion that interviewers know more than they actually know. When presented with a presumptive statement or question, the interviewee will either confirm the presumption or make corrections if the presumption is wrong.

The presumptive statement or question places the interviewee in a position to either confirm the presumption or forces the interviewee to provide additional information to correct the presumption.  People feel compelled to correct presumptive statements or questions, especially if the presumption is wrong. People have a strong desire to be right and a stronger desire to correct others. 

Instead of asking, “Do you know a certain person,” ask “When did you first meet the person?” Instead of asking your kids, “Do you use drugs?” ask them “When was the last time you used drugs?” The presumptive question places your kids in a dilemma. The presumptive question gives the illusion that you know more about their drug use than they originally believed. Your kids' reaction to this presumptive question may shed light on their drug use. If your kids do not use drugs, they will likely protest that you doubt their veracity.  In this event, you reply, “Of course you don't use drugs. I believe you.” If your kids do use drugs, then they will likely hesitate when they answer the question because they have to evaluate if you really possess knowledge about their drug use.

After they hesitate for a split second, ask them, “Did you really think I wouldn’t find out?” This follow-up presumptive question places your kids in an even more difficult dilemma. If they answer, “Yes,” then they admit to drug use. If they answer, “No,” then they admit to drug use. The only acceptable answer is, “Find out about what?” When presented with two options, liars feel obligated to pick one of the two options. People who tell the truth have a universe of answers to choose from and do not feel obligated to select one of two possible answers. The presumptive statement or question can be used in a variety of personal, social, and business environments to uncover the truth. 

For more tips and techniques to detect deception refer to The Like Switch: An Ex-FBI Agent’s Guide to Influencing, Attracting, and Winning People Over.