This scenario best exemplifies the "false consensus" effect.
The false consensus effect happens when we overestimate the quantity of other individuals (or degree to which other individuals) share our sentiments, convictions, and practices. In this way, once in a while people have a tendency to trust that others are more like them than is really the case.
Simply put, a representative democracy is a system of government in which all eligible citizens vote on representatives to pass laws for them. A perfect example is the U.S., where we elect a president and members of the Congress. We also elect local and state officials.
Because the Europeans had already been exposed to the diseases and had built an immunity to it, and the Native Americans hadn't, hope this helps
