Why do we view options as more distinct when evaluating them simultaneously?

The 

Distinction Bias

, explained.
Bias

What is Distinction Bias?

Distinction bias describes how, in decision-making, we tend to overvalue the differences between two options when we examine them together. Conversely, we consider these differences to be less important when we evaluate the options separately.

Where this bias occurs

Imagine that you’re in the process of choosing between going to get coffee at one of two cafés on your way to work. One café makes stronger coffee, which you’re a fan of. However, you’re running late, so you would have to make a detour to go to that café. The other coffee shop is right next to your work, so you decide to go there instead. Normally, you enjoy the coffee there but, today, because you’ve been comparing it to the stronger coffee from the other café, the coffee seems particularly weak and watery. As a result, you don’t enjoy your drink nearly as much as you usually do. Two important concepts at play here are joint evaluation and separate evaluation. Joint evaluation is when we examine two options simultaneously, while separate evaluation is when we examine them separately. In this case, when using a separate evaluation, we rate both coffees favorably. However, using joint evaluation and comparing the two coffees directly makes their differences more salient.

Sources

  1. Hsee, C. K., & Zhang, J. (2004). Distinction Bias: Misprediction and Mischoice Due to Joint Evaluation. Journal of Personality and Social Psychology, 86(5), 680–695. doi: 10.1037/0022-3514.86.5.680
  2. Wilson, T.D. and Gilbert, D.T. (2013). The Impact Bias is Alive and Well. Journal of Personality and Social Psychology. 105(5), 740-748. doi: 10.1037/a0032662
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About the Authors

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Dan Pilat

Dan is a Co-Founder and Managing Director at The Decision Lab. He is a bestselling author of Intention - a book he wrote with Wiley on the mindful application of behavioral science in organizations. Dan has a background in organizational decision making, with a BComm in Decision & Information Systems from McGill University. He has worked on enterprise-level behavioral architecture at TD Securities and BMO Capital Markets, where he advised management on the implementation of systems processing billions of dollars per week. Driven by an appetite for the latest in technology, Dan created a course on business intelligence and lectured at McGill University, and has applied behavioral science to topics such as augmented and virtual reality.

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Dr. Sekoul Krastev

Dr. Sekoul Krastev is a decision scientist and Co-Founder of The Decision Lab, one of the world's leading behavioral science consultancies. His team works with large organizations—Fortune 500 companies, governments, foundations and supernationals—to apply behavioral science and decision theory for social good. He holds a PhD in neuroscience from McGill University and is currently a visiting scholar at NYU. His work has been featured in academic journals as well as in The New York Times, Forbes, and Bloomberg. He is also the author of Intention (Wiley, 2024), a bestselling book on the science of human agency. Before founding The Decision Lab, he worked at the Boston Consulting Group and Google.

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