Have A Gut Feeling? Bias vs. Logic in Decision Making


Home / Have A Gut Feeling? Bias vs. Logic in Decision Making

Logic plays a bigger role in gut thinking than believed: Photo by Webmaster-CHX

Have you ever been in a situation where you were thinking one thing, but your gut was telling you another? Have you ever followed your gut instinct, and known that you’re making a mistake? What about talking yourself into the gut feeling using rationalization? Chances are, you have followed your gut at some point in your life, and according to new research, logic plays a much larger role than believed.

No Guts, No Glory Tested

In a new study, entitled “Bias and conflict: A case for logical intuitions,” led by Dr. Win De Neys from the University of Toulouse in France, researchers examined the logic process in subjects. Researchers posed questions while measuring brain activity – the scans showed that people not only tended to go with their intuition, resulting in the wrong choices, but also were aware of being wrong as they made those choices.

This study focused on the conflict between making a gut decision, and the knowledge that the choice was wrong from the beginning. Subjects in the study consistently made the wrong assumptions, even as they knew that they were making the wrong decision.

What’s wrong with this picture? Photo by Mitchazenia

Logical Interpretation of Gut Reactions

For people who think with their guts, the common answers involved making assessments that were not provided. This shows that gut thinking adds details from the provided information to make a judgment on the situation. This type of thinking was not altered by the intelligence of the individual, meaning that every person is able of making these mistakes, regardless of education.

Educational programs can improve logical thinking and reduce bias in society: Photo by Carla

Gut Feelings vs. Logical Conclusions… Continued


In the course of the interview, Decoded Science also asked Dr. De Neys about the educational background of the test subjects.

Did the level of education of test subjects make a difference in the results? Dr. De Neys responded,

In our work on conflict detection we find very little individual differences. Even the least educated and cognitively least gifted participants detect that their intuitive inferences conflict with logical norms. That being said, you need to take into account that we typically test college students (as 95% of all experimental studies in cognitive science). Of course, even college students with the lowest IQ scores or from the poorest colleges are still “college” students and pretty well educated if you look at the population at large. Currently we do not know yet whether our results generalize to really poorly educated samples. I suspect that people need some basic formal education (let’s say at least at the middle school level) to master the logical intuitions that I discuss. But because the logical principles we are looking at are so basic I’m pretty confident that any adult who finished high school will demonstrate the logical sensitivity I talked about.

Short answer: we didn’t really test it but my gut feeling tells me that education is not going to have a substantial impact.

How Society Benefits From Logic vs. Intuition Research

When asked about the implications of this research, Dr. De Neys replied,

Well, if I’m right and people do detect that their intuitive inferences conflict with logical considerations this has important implications for the design of intervention programs to help people avoid biased thinking. As a society, we are already spending quite some (educational) effort to make people better at logical reasoning, right? If we want to help people and train them to avoid being biased, we need to know why they are biased in the first place. Our work suggests that reasoning errors should not be attributed to a lack of logical knowledge. People do detect that their intuitive judgments conflict with logical norms. The problem seems to be that people simply fail to inhibit the salient intuitive response. This suggest that people will benefit most from a training aimed at increasing their inhibitory processing.

In short, if we, as a society, believe that is is important to train people to avoid biased thinking we need to figure out why people are biased first. That’s why research that examines whether people have some implicit logical knowledge really matters.

Finally, when Decoded Science asked Dr. De Neys about the most surprising result of this study, he responded,

The fact that we found so little individual differences. Even though we tested college students there is a very influential tradition in the decision-making field (e.g., the Nobel prize winning work of D. Kahneman) that suggests that the average college-educated adult does not detect the biased nature of his/her intuitive inferences. One of the reasons that the original Heuristics and Biases studies of Kahneman and colleagues became so notorious is precisely the fact that they suggested that even educated adults disregard logic. Our findings indicate that this received view needs to be qualified. Although people often give a logically inappropriate response, they at least seem to detect that their answer is not fully warranted.

You wouldn’t be surprised to find this with the brightest students who might err by accident but we found it even for the most biased reasoners in our studies who consistently failed to solve any of the problems we presented them.

This type of biased thinking can be dangerous at higher levels, as well as in our personal relationships. For example, we believe that our leaders are using logic and resources to make decisions, but if they are making policy decisions based on gut reactions, we could be making huge mistakes as a nation. On the other hand the bias and gut instincts discussed in this study could end up playing a positive role in the acceptance of minorities and other non-mainstream belief structures. There are many groups and individuals in America who are fighting for acceptance and understanding, and further research and education in the area of instinctive biases may result in future generations being able to eliminate illogical judgments, and may even improve our ability to think rationally about any subject.


De Neys, W. (2011). Bias and conflict: A case for logical intuitions. Perspectives on Psychological Science. (January 2012). Accessed December 30, 2012.

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