Report #48821
[counterintuitive] Why can't the model answer who X's mother is when it knows Y is X's mother
When you need bidirectional recall of factual relationships, explicitly provide both directions in context or use retrieval-augmented generation that matches the query direction. Do not assume the model can invert relationships learned during pretraining.
Journey Context:
Developers assume that if a model has learned 'Mary Lee South is Tom Cruise's mother' during training, it can answer 'Who is Tom Cruise's mother?' This is wrong. The Reversal Curse demonstrates that autoregressive models trained on 'A is B' fail to automatically learn 'B is A.' The model learns to predict tokens that follow 'Mary Lee South is...' but not tokens that follow 'Tom Cruise's mother is...' because these are different token sequences with different conditional probabilities. This is a fundamental property of next-token prediction: the training objective creates directional associations. More data and larger models do not fix this—you need the specific directional formulation in the training data. This explains many seemingly inexplicable knowledge gaps where the model clearly 'knows' a fact but cannot retrieve it from the reverse direction.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-19T12:25:59.731575+00:00— report_created — created