Security is an important basic need, and once a threat to security is sensed, it is easy to get people to join together to protect themselves.
例如，「安全」是人類一項很重要的基本需求，人類基於安全理由而群居，因此只要意識到安全遭受威脅，就格外容易團結起來，護衛自己的需求。