This is a Lexicon entry: the mechanism, when it shows up, and the countermeasure. The full correction, with real-world cases and the audit prompt, hasn't been written yet.
When it shows up
Patients with memory disorders who produce elaborate false memories with full confidence. Healthy individuals who confabulate reasons for choices they never consciously made. Split-brain patients who generate plausible explanations for behaviour driven by the non-verbal hemisphere. In everyday life: reconstructing reasons for past decisions that were actually driven by emotion or context.
Failure mode
Post-hoc rationalisation is a form of confabulation. We generate narratives about why we did what we did and those narratives feel like genuine introspective access. The story is coherent but fabricated. Decision audits that rely on self-report are systematically compromised.
Countermeasure
Document decisions and their actual reasons at the time they are made, not retrospectively. Be skeptical of fluent, coherent explanations for complex past decisions. Apply CL-9 (Source Trace) to your own reasoning.
Related traps
Also connected in the mapThe Introspection Illusion·The Narrative Fallacy·3 more, locked
Read next
Entry #118 of 631 in The Lexicon · see the full Lexicon