If something big happens, something just as big must’ve caused it - that’s what our intuition says. Humans tend to believe that major events result from major causes even though that’s rarely the case. In retrospect, that may make sense. But in fleeting moments, it’s hard to imagine catastrophic consequences from small insignificant causes.
This ‘Major-Event-Major-Cause’ heuristic, also called the Proportionality Bias, occurs when we instinctively conclude that the magnitude of the cause should match the magnitude of its effects. It also explains why we ascribe large conspiracies or motivated neglect to events that are objectively small in magnitude at the time of occurring but have large effects - like exposure to the coronavirus, sloppy use of a condom, or a typo in an official document.
The Representativeness Heuristic can also create this effect. With Representativeness Heuristic, people are inclined to believe that two things belong together because they superficially match each other.
Our intuition follows the notion that something big goes with something big while something small goes with something small. A reason for this matchmaking can be explained by the lesser mental processing needed to make sense of an event by equating the magnitude of a cause to the related effect. It over-simplifies a scenario to exclude complex intermediate steps that incrementally convert insignificant precursors into amplified consequences over numerous stages.
However, this linear approach between cause and effect is seldom true. For example, a high effort to use a pillow to break a wall will probably not affect when the wall breaks. Is it fair to blame that pillow for conspiring not to use its full power potential? Unlikely.
Such reasoning often occurs when we need to explain or justify big events. Patients may fail to acknowledge that exposure to a germ could leave them broken as a result of expensive medical treatments. Or a seemingly innocent walk in the park could expose them to a disease-causing germ. Even if it doesn’t make sense, a desperate patient might think the doctors are out to make money, and that their suffering is just a side effect of unnecessary medical treatments.