70-20-10 Rule (learning)

Biological Parallel

Young chimpanzees acquire nut-cracking through 70% trial-and-error practice, 20% observation of skilled adults, and 10% direct teaching where mothers position hands correctly. This ratio reflects the energetic economics of knowledge transfer: practice is free but slow, observation is efficient but limited by model availability, and teaching is powerful but costly in attention. Cultural transmission in cetaceans, corvids, and primates follows identical distributions—the proportions emerge from optimizing learning speed against teaching costs across the three available modalities.