After an outcome is known, the tendency to over-estimate how foreseeable it was beforehand — the "I knew it all along" effect, also called creeping determinism. Memory of one's prior judgements is rewritten to fit the result.
In intelligence analysis
- Post-mortems conclude a failure "should have been seen", discouraging honest appraisal of what was actually knowable at the time.
- Erodes the ability to learn from a track record, because past uncertainty is systematically forgotten.
- Feeds Overconfidence Bias in future work ("we were basically right last time").
Countermeasure
- Keep written prior judgements with explicit Estimative Language, and score them against outcomes — so hindsight cannot rewrite what was actually said.
- Structured lessons-learned that distinguish "foreseeable at the time" from "clear only in retrospect".
Related
- Cognitive Bias — the taxonomy this bias sits within
- Overconfidence Bias — the downstream effect on future confidence
- Estimative Language — the written record that defeats hindsight