Answer:
The terms “in-group” and “out-group” are social science terms. In this context: An “in-group” is a group you are part of (genetically, culturally, or ideologically), while an “out-group” is a group you aren’t part of. More specifically, our in-group is a group we are a part of or identify with (genetically, culturally, or ideologically), and our out-group is the opposite, a group we don’t identify as being a part of or aren’t a part of (genetically, culturally, or ideologically).