The Secret of Our Success

1. Culture, not innate intelligence, drives human success

We humans are not like other animals.

Cultural learning is key. Humans' ecological dominance stems from our ability to learn from others and accumulate knowledge over generations. This process, called cumulative cultural evolution, allows us to adapt to diverse environments without genetic changes. Our success lies not in individual intelligence, but in our collective cultural knowledge.

Lost explorers illustrate this point. European explorers often struggled to survive in unfamiliar environments, despite their education and technology. Meanwhile, indigenous peoples thrived in these same environments using culturally transmitted knowledge about local plants, animals, and survival techniques. This demonstrates that cultural adaptation, not innate intelligence, is crucial for human survival and success in diverse environments.

• Examples of cultural adaptations:
  • Complex food processing techniques (e.g., manioc detoxification)
  • Specialized hunting tools and strategies
  • Detailed knowledge of local flora and fauna
  • Social norms and institutions that facilitate cooperation

2. Cultural evolution shapes our bodies and brains

Our ability to survive and thrive as hunter-gatherers, or anything else, across an immense range of global environments is not due to our individual brainpower applied to solving complex problems.

Biological changes through culture. Cultural evolution has driven genetic changes in humans, shaping our anatomy and physiology. This process, called culture-gene coevolution, has resulted in numerous adaptations that make us uniquely human.

Examples of culture-driven adaptations:

• Smaller guts due to cooking and food processing
• Weaker muscles but increased endurance for persistence hunting
• Larger brains capable of storing vast amounts of cultural information
• Extended childhood for prolonged learning
• Menopause to allow for knowledge transmission to younger generations

These changes demonstrate how cultural practices and innovations have feedback effects on our biology, creating a unique evolutionary pathway for humans.

3. Social norms and institutions amplify cooperation

Our species cooperation and sociality is deeply influenced by and highly dependent on culturally evolved social norms, which makes us rather unlike other animals.

Norms extend cooperation. Social norms and institutions allow humans to cooperate on scales far beyond what our innate psychology would permit. These culturally evolved rules and practices harness and extend our natural tendencies for kinship and reciprocity.

Key aspects of norm-based cooperation:

• Third-party monitoring and enforcement of rules
• Reputation systems that incentivize prosocial behavior
• Rituals and ceremonies that create social bonds
• Kinship systems that extend cooperation beyond close relatives
• Marriage norms that create alliances between groups

These cultural adaptations enable humans to form large, complex societies and cooperate with unrelated individuals, setting us apart from other species.

4. Intergroup competition fuels cultural adaptation

Intergroup competition provides one important process that can help explain the spread of norms that foster prosociality.

Competition drives innovation. Intergroup competition, including warfare and economic rivalry, has been a powerful force in human history. This competition favors the spread of cultural practices and institutions that make groups more cohesive, productive, and militarily successful.

Mechanisms of intergroup cultural adaptation:

1. Direct conflict and replacement
2. Differential group survival in harsh environments
3. Migration to more successful groups
4. Copying of practices from prestigious or successful groups
5. Differential reproduction rates between groups

This process explains the spread of complex technologies, social institutions, and belief systems across human societies. It also highlights why human groups often show strong in-group favoritism and out-group hostility.

5. Collective brains generate cumulative cultural evolution

The secret of our species' success resides not in the power of our individual minds, but in the collective brains of our communities.

Innovation through interconnection. The power of human cultural evolution comes from our ability to learn from many individuals and combine ideas in novel ways. This process, driven by our collective brains, allows for the accumulation and refinement of knowledge over generations.

Factors influencing collective brain power:

• Population size
• Social interconnectedness
• Longevity (allowing for extended learning and teaching)
• Technologies for information storage and transmission (e.g., writing)

The collective brain explains why larger, more interconnected societies tend to have more complex technologies and larger bodies of knowledge. It also highlights the importance of maintaining diverse knowledge sources and social connections for innovation and problem-solving.

6. Languages evolve as adaptive communication systems

Languages arise from long-term cumulative cultural evolution.

Cultural adaptation of language. Like other aspects of culture, languages evolve to become more efficient and expressive over time. This process is shaped by the needs of speakers and the constraints of human cognition and physiology.

Examples of language adaptation:

• Sonority adjustments for different acoustic environments
• Expansion of color terms and number systems
• Development of grammatical tools through grammaticalization
• Optimization of word length and phoneme inventories

These adaptations show that languages are not static or arbitrary systems, but rather finely tuned tools for communication that reflect the needs and experiences of their speakers.

7. Self-domestication through social norms shapes human psychology

We humans do, of course, construct causal models of how the world works. However, what's often missed is that the construction of these models has long been sparked and fostered by the existence of complex culturally evolved products.

Norm psychology emerges. Living in a world governed by social norms has shaped human psychology through a process of self-domestication. This has resulted in uniquely human traits and cognitive abilities.

Key aspects of human norm psychology:

• Internalization of social rules as personal goals
• Strong emotional reactions to norm violations
• Tendency to infer and follow implicit social rules
• Automatic imitation and conformity in many contexts
• Prestige-biased learning from successful individuals

This norm psychology allows humans to navigate complex social environments and rapidly acquire the cultural knowledge necessary for survival and success in their societies. It also explains many aspects of human behavior that seem irrational or maladaptive from an individual perspective but make sense in a social context.

Human nature is thus deeply shaped by our cultural evolution, making us a fundamentally cultural species. Our success lies not in our individual intelligence or instincts, but in our ability to learn from others and participate in the collective accumulation of knowledge and practices that define human cultures.

Last updated: January 25, 2025