Mental Set (Einstellung Effect)
People often impose unnecessary constraints on problems, such as assuming blocks must touch each other, which makes solving simple problems difficult.
THE IDEA
This cognitive bias describes the tendency to rely on familiar methods or assumptions when solving problems, even when they are not required. In a block arrangement task, participants assumed that blocks had to be arranged in a single configuration where they all touch each other. This artificial limit, introduced out of convenience, made a simple problem—which actually allowed for separate, non-touching arrangements—seem difficult. The mental set blinds individuals to alternative solutions that are outside the assumed framework.
When to use it
Solving puzzles that require unconventional thinking, such as the nine-dot problem.
Brainstorming sessions where participants unintentionally adhere to unstated rules.
Product design: avoiding assumptions that limit innovation.
Everyday decision-making: challenging the default approach to a task.
FROM THEORY TO EVERYDAY LIFE
In practice
Block Arrangement Problem
Participants are given blocks and asked to arrange them in a way that satisfies certain conditions. Most assume the blocks must touch each other in a single cohesive arrangement, ignoring the possibility of separate groups of blocks. This unnecessary constraint makes a simple problem much harder.
A MOMENT TO REFLECT
Put it to work.
When have you found yourself stuck on a problem because of an assumption that wasn't actually required?
How can you train yourself to question implicit constraints in a task?
What strategies can help break a mental set and see new possibilities?
Often confused with
CONTINUE THE CONVERSATION
Source texts
- Lateral Thinking A Textbook of Creativity (Edward de Bono)