What is invisible cultural norms?

Invisible cultural norms is a concept in personal epistemology: Your cultural assumptions are invisible to you until you encounter a different culture.

Example: An American engineer gives direct, critical feedback in a code review: 'This approach is wrong — here's why.' They consider this helpful and efficient. Their Japanese colleague reads the same comment as a public humiliation that damages the relationship. Neither person is being unreasonable. They're operating from cultural defaults about directness, face-saving, and what 'helpfulness' means — defaults that were invisible to both until the collision.

This concept is part of Phase 9 (Context Sensitivity) in the How to Think curriculum, which builds the epistemic infrastructure for context sensitivity.