Fallacy of the Single Cause

The cognitive error of attributing an outcome to one cause when it actually results from multiple interacting causes—oversimplifying complex causation into a simple story. 'The project failed because of bad leadership.' 'The company succeeded because of great products.' 'The economy crashed because of housing.' Each of these has a kernel of truth but radically oversimplifies by ignoring the web of contributing causes. The single-cause fallacy is driven by the narrative fallacy (single causes make better stories) and cognitive load reduction (multiple causes are harder to think about). The result: interventions target one cause while the other causes continue to operate.

When to use it

When post-event analysis converges on a single explanation too quickly; when interventions address one cause while the outcome persists (other causes are still operating); when complex outcomes are being oversimplified for narrative convenience; when causal analysis needs to capture the full web of contributing factors.

How it can help

For any outcome: generate at least three contributing causes before settling on an explanation. The practice: when you identify 'the cause,' ask 'what ELSE contributed?' Repeat until you have a web of contributing factors. Then: assess relative contribution rather than selecting one winner. In organizational post-mortems: reject single-factor explanations ('we failed because of X') in favor of causal mapping ('these five factors interacted to produce the failure, with X being the most significant but not sufficient'). This produces more effective interventions because it addresses the causal web, not just one strand.