Challenging assumptions

Assumptions and clichés are the patterns that shape much of our thinking. A cliché can be a stereotyped phrase, a habitual way of describing something, or even an idea itself. While we often focus on rearranging such standard ideas into new combinations, lateral thinking demands that we also restructure the very patterns we take for granted. Many assumptions persist not because they are continually re‑validated but simply through historical continuity. This is not a call to undermine every assumption and fall into indecision; on the contrary, acknowledging that any pattern can be challenged gives us greater freedom to use assumptions without becoming imprisoned by them.

The shape puzzle analogy

Imagine you are given three shapes and asked to arrange them into a single, easily described form. Finding a satisfactory arrangement may prove difficult as long as you treat each piece as fixed. If, however, you re‑examine the shapes themselves – for instance, by splitting the larger square in two – a simple overall arrangement suddenly becomes obvious. Someone who had assumed the pieces were unalterable might cry “cheating.” But the very protest reveals the hidden boundary: the assumption that the shapes could not be changed.

Boundaries in problem solving

Every problem‑solver imposes boundaries to make the search for a solution more manageable. Knowing an address is north of the Thames narrows the search; knowing it is within walking distance of Piccadilly Circus narrows it further. Such limits are useful when the information is reliable. A limit merely assumed, however, can exclude the place where the answer lies. When another person solves the problem by stepping outside those limits, the instinctive reaction is “cheating” – yet the real trap was the boundary, not the solution. A wrong boundary can make a problem as impossible to solve as looking for a south‑London address exclusively north of the river.

Examples

• The flower seller: Late one Saturday morning a flower seller offers a large bunch of carnations for a surprisingly low price. The buyer assumes the entire bunch in the seller’s hand is the bargain and pays. The seller then detaches a small, pre‑wrapped bunch of about four carnations and hands them over. The assumption about what “a large bunch” referred to was entirely the buyer’s own.

• The housing estate: At the ceremonial opening of a new housing estate, everything appears slightly undersized – ceilings, doors, windows. The cause is eventually traced to someone having cut an inch off the end of every measuring stick used by the workmen. Because the sticks were the very tools for verifying everything else, no one thought to question their accuracy.

• The pear brandy: A bottle of Swiss pear brandy contains a fully grown pear. How did the pear get inside? Most people assume the bottle was sealed around an adult pear – either the neck was closed afterwards or the bottom was affixed later. The critical assumption is that the pear entered the bottle as a fully grown fruit. In reality, a branch bearing a tiny bud was inserted through the neck, and the pear grew inside the bottle.

The practical question is which limits belong to the problem and which you have added. Assumptions make everyday thinking manageable; noticing them lets you test or revise the ones that obstruct a solution.