Concept · Cognitive Bias: Memory biases and distortions

Spacing effect

Origin: Ebbinghaus, 1885

Biological Parallel

Trees growing in seasonal climates develop stronger wood than those in constant conditions—intermittent stress triggers adaptation that continuous exposure cannot. Spaced repetition exploits memory reconsolidation: each retrieval slightly weakens then strengthens the trace, and optimal spacing maximizes this reconsolidation benefit. The effect mirrors biological training: recovery intervals build capacity more than continuous activation.