You can find the answer to this question by reading in Chapter 4. Diamond gives the answer most clearly in Figure 4.1. At the bottom of that flow chart are four general kinds of proximate factors that allowed farmers to dominate hunter-gatherers. These factors include:
- Epidemic diseases. These arose among farmers and not among hunter-gatherers. When the latter were exposed to them, they tended to die in large numbers.
- Political organization and writing. Farmers come to need organized governments to govern their larger populations. These help them fight more effectively and dominate hunter-gatherers.
- Technology. Food surpluses can be used to feed specialists in technology. These technologies, like guns and steel weapons, can be used to dominate hunter-gatherers.
- Horses. These were used to good effect by farming societies both as pack animals and war animals.