14. Why did Pizarro and the Spaniards pass disease to the Incas and not the other way around?

Pizarro and the Spaniards passed diseases to the Incas and not the other way around primarily due to the following reasons:1. **Population Density and Urbanization**: The Incas had a highly dense population and were an urbanized society with cities like Cusco and Machu Picchu. This close living quarters facilitated the rapid spread of infectious diseases among them.2. **Lack of Immunity**: The Incas had no prior exposure to Old World diseases such as smallpox, measles, and influenza. As a result, they had no immunity to these diseases, making them highly susceptible and vulnerable when exposed.3. **Introduction by Europeans**: When the Spanish arrived in the Americas, they brought with them diseases that were endemic to Europe. These diseases were unintentionally carried by the Europeans and introduced to the native populations, who had no resistance.4. **Impact on Social Structure**: The diseases caused significant social disruption among the Incas. Epidemics led to massive population declines, weakened social structures, and made it easier for the Spaniards to conquer and control large territories.5. **European Adaptation**: In contrast, the Europeans had been exposed to a variety of diseases over centuries and had developed some level of immunity. While they also suffered from diseases in the New World, the impact was less devastating on their populations compared to the catastrophic effects on the Incas.In summary, the combination of high population density, lack of immunity, and the introduction of Old World diseases by the Europeans led to the devastating impact on the Inca population, facilitating the Spanish conquest.