The post examines cultural evolution, arguing that while within-culture evolution is effective, between-cultures evolution is too slow and weak to justify cultural practices like opposition to gay marriage. Longer summary

This post discusses the concept of cultural evolution, distinguishing between two types: within-culture and between-cultures evolution. The author argues that while within-culture evolution (like Inuit survival techniques) is obvious and effective, between-cultures evolution (like arguments against gay marriage) is much weaker and slower. The post challenges the idea that cultural practices persisting over time necessarily prove their value, pointing out that cultural changes often take centuries and that the advantages of specific cultural traits are hard to isolate. The author concludes that appeals to intercultural evolution to justify cultural practices are on shaky ground, and that intracultural evolution can't override people's own assessments of their happiness and well-being. Shorter summary