In n' Out-Groups

What groups are you in? Imagine all the different groups that you are a part of. Friends, family, race, gender, school, sports, religion, culture, and many more. Many people don't realize how many in-groups they are a part of. An in-group is a group that an individual feels as though they belong, like a member, due to common interests and hobbies. An out-group are basically a group that an individual is not a part of, maybe even takes complete opposite opinion on them. Members of an in-group immediately get along due to their common interests, and also develop favoritism and judgements against groups that are not "them". For example, we did an activity in class where our teacher split us up into 2 groups depending on the color shirt you were wearing, black or colored shirt. A leader in each group was to right down ideas on why the other group was wearing a shirt that was not same colored as theirs. When the whole class got together again, the leaders shared their lists. To surprise, much of the list were judgements that probably weren't true. The groups assumed things about the other group without a logic reason, just "because". A personal example was when I was involved in a sport. Whenever we had competitions, our team would make mean remarks about the others performance, but we don't really know their issue. Maybe they had a migraine that day, or sprained their ankle and tried their best but couldn't do their best. People should treat others the way they want to be treated.