Implicit Bias:
Implicit bias refers to the unconscious preference or lack thereof toward specific groups or ideas. This is a preference which arises automatically, with no conscious intention. For example, someone might subconsciously feel more comfortable around people who are the same race as them rather than people of other races. While there isn't any conscious intention, implicit bias can affect one's decision making without them thinking about it.
Resources:
Harvard's Implicit Association Tests (IAT):
A popular way for people to test their implicit biases is with Harvard's Implicit Association Tests (IAT). The IAT's test implicit bias by having people quickly sort items into groups. For example, a test may ask people to sort items into the categories "Christianity and words with a positive connotation" and "Judaism and words with a negative connotation". The test would then switch the categories so that Christianity is now grouped with the negative words. The test looks at how fast the items were sorted depending on how the categories were set. If one category grouping is considerably faster than the other, then that is a signal of possible implicit bias.
Implicit Bias Video:
Implicit bias is just one factor which affects the social and political lives of people; however, people's lives are affected by many factors which influence each other. Understanding the complexity of the world, people, and their human experiences through these many factors is the core of the idea of intersectionality. It is a tool for understanding the implicit biases which affect people and ultimately give some people more power and influence over others.