1) Humans have an innate tendency to categorize people and seek patterns in order to simplify a complex world, preferring familiar things and mistrusting unfamiliar things. 2) Unconscious biases form from upbringing, past experiences, beliefs, culture, social status, media, and lack of familiarity and can influence how we assess others. 3) Common unconscious biases include stereotyping, attribution bias, in-group thinking, confirmation bias, and the bandwagon effect, which can negatively impact decisions about others.