Tribalism plays a big role in how humans interact, creating an "us versus them" mindset. This idea has been around since ancient times when people lived in tribes, and it still affects how groups in society behave today. We look at how the brain helps create feelings of belonging and loyalty through chemicals like oxytocin, dopamine, and cortisol, but these same feelings can also lead to mistrust or conflict with outsiders. The discussion also dives into how tribalism shows up in things like sports, religion, and politics, where it can either bring people together or push them apart. Finally, we ask whether tribalism helps us survive or causes more problems, encouraging people to think about their own groups and biases.