More on the Role of Weapons for Evolution

Weapons reduce the distance between the strongest and weakest members of a group, especially projectile weapons, and change what it means to become a powerful and dominant leader within a social group. When weaker individuals can band together in coalitions with the use of weapons to topple a physically dominant alpha, new skills become more valuable than physical dominance alone.


“Once weapons enter the picture,” write Kevin Simler and Robin Hanson in The Elephant in the Brain“physical strength is no longer the most crucial factor in determining a hominid’s success within a group. It’s still important, mind you, but not singularly important. In particular, political skill – being able to identify, join, and possibly lead the most effective coalition – takes over as the determining factor.”


Political skills are not so important if your species rarely interacts in groups. If you live mostly in isolation, occasionally meet another member of your species to mate or fight over food, being politically skilled is not too important. Hanson and Simler argue that weapons and a change in power dynamics is what set the human brain on a path toward ever greater evolution. Political skill requires mental acuity, deception, the ability to signal loyalty, and the ability to relate and connect with others. The better your brain is at doing the complex work required for these skills, the more likely you will survive long enough to reproduce. This created the environment for our brains to begin to enlarge, since individuals with bigger brains and more intelligence were generally favored over those who were a little less cognitively capable and therefor less politically and socially skilled.


I think it is interesting and important to consider the factors that shaped human evolution. Understanding how our brain came to be the way it is helps us understand why we act the way we do, why we see certain types of biases in thinking, and how we can overcome mistakes in our ways of thought. By acknowledging that our brains developed to be devious, and that our brains did not develop to give us a perfect view of reality, we can better think about how we design institutions and settings to help us think in the most productive ways possible.

The Political Role of Weapons for Our Early Ancestors

Weapons are in interesting consideration for early human evolution and how we ended up in the place we are with large brains and strong social groups. Kevin Simler and Robin Hanson address the importance of weapons in their book The Elephant in the Brain. Weapons change the value of physical strength and the nature of conflict on the individual and group levels. They alter the threats and defenses that our early ancestors faced and could mount.


“Weapons are a game changer for two reasons.” write Hanson and Simler, “First, they level the playing field between weak and strong members of a group. … Another way weapons alter the balance of power applies to projectile weapons like stones or spears. Such distance weapons make it much easier for a coalition to gang up on a single individual.”


Physical force has been a dominating aspect of human relationships (and probably early human ancestors’ relationships), but we don’t live in societies where just the most physically dominant individuals rule. Weapons are a big part of why this is the case. Once we could hurl projectiles, even just heavy or sharp rocks, at opponents, our social grouping had to change. Coalitions could push back against a dominant individual who did not care about the well being of the group or of others. The role of politics and cooperation could naturally be expected to rise in a system where physical dominance was not the sole determinant of leadership and power.


What weapons did, Hanson and Simler argue and I will discuss more tomorrow, is create a system that favored brain development. Social intelligence and intellectual capacity became more valuable when coalitions could rule with weapons, and that created a space where the brain could evolve to become larger and more complex. If pure physical dominance was the best predictor of power and of passing along our genes, then we would not have expected our early ancestors to begin evolving in a way that favored the development of a large and highly energy dependent brain. By bringing physical prowess down a level, weapons it seems, helped further the evolutionary growth of the human brain.