We live in an age of information. In theory, we can learn just about anything about anyone or any topic at the touch of a button. All this information should allow us to make super-informed, data-driven decisions all the time.
But the widespread availability of information does not mean that you actually use it. In fact, decades of research in psychology and behavioral science find that people readily make data-poor snap judgments in a variety of instances. People form lasting impressions of others in the span of milliseconds, evaluators judge teachers in less than a minute and consumers make shopping decisions based on little deliberation. Even voting decisions can seemingly be predicted from preliminary impressions formed during incredibly brief time periods.