When a group of people come together, they form a crowd. Strangers connect and share a common purpose and identity. It's an exhilarating experience. At football matches, music festivals and protest marches, people become energised in groups. They can be frightening places when they erupt in violence, or peaceful forms of protest when we try to change social norms. In this edition of the Why Factor, Sandra Kanthal asks why we take courage from a crowd.

(Image: Large crowd of people, Credit: Shutterstock)