Complexity Bias describes the phenomenon whereby people intuitively rate complex explanations or solutions as more convincing and superior than a simpler alternative. Apparently, a complicated approach gives people a better feeling of not having overlooked anything. As a result, a simple but possibly more efficient solution is sometimes underestimated or even dismissed. People who are able to express themselves in complicated terms are considered more competent than someone who proposes a simple solution in a few words.

We also tend to value more choices as a "qualitative" improvement, which can lead to a distorted perception of efficiency. This bias can lead to unnecessarily elaborate processes in areas such as product design, marketing and strategy, although a simple approach would often be more productive. Jacob Nielsen, for example, found that usability studies do not have to be unnecessarily large to identify all problems. From about five to eight test participants, the survey provides most of the important usability problems, while additional participants often only repeat known problems with similar frequency, without providing significant new insights. (See Nielsen, J. (2000). Why You Only Need to Test with 5 Users, Nielsen Norman Group)

Origin

This bias is closely related to other cognitive biases such as the Availability Effect, the Halo Effect and the Dunning-Kruger Effect and has been analyzed in several psychological works, including the works of Tversky and Kahneman.

  • Kahneman, D. (2011). Thinking, Fast and Slow. New York: Farrar, Straus and Giroux.
  • Farnam Street (2020). Complexity Bias: Why We Prefer Complicated to Simple

Application in UX and UI design

Taking Complexity Bias into account is not entirely irrelevant in UX and UI design either. For example, extremely minimalist solutions can be perceived as inadequate or even unprofessional by target groups who expect a particularly specialized product, as they lack the necessary complexity and depth of detail to meet specific needs. In these cases, it is crucial to find the right balance between simplicity and a sense of expertise so as not to give the impression that essential functions or information have been omitted.

Impact on the User Experience

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Further information