Really, one could expect to find crowds of people standing in front of the shelves in supermarkets taking ages to study the huge selection of different yoghurt. The fact that most people are able to make a decision very quickly is owed to a trick used by the human brain: It narrows the selection down to the two most promising options, as researchers led by Sebastian Gluth from the University of Basel report in the journal “Nature Human Behaviour”.

In several stages, the researchers asked 139 test subjects to choose between three different, constantly changing foods. With the aid of eye-tracking technology, they observed what the attention of the participants focused on.

They discovered that the test subjects’ attention was not evenly distributed, but would increasingly focus on the two most promising options. The easier the participants found it to eliminate the worst option, the faster they were able to choose between the two remaining candidates.

Decision-making in a real-life environment

For a long time, decision-making processes were researched using only two options, but for some years now, the focus has shifted to decisions between three or more candidates. Here, different mechanisms can apply than with only two options. For example, the addition of a third option can make one of the two original options more attractive and thus overturn the previous decision.

“One objective of our research is to understand how people navigate a world of increasing choices, such as in online shops or large shopping malls,” Sebastian Gluth explains.