I want you to put your hand up if you've ever wanted to get back at someone. Someone who wronged you, someone who hurt you, or someone who annoyed you, even if it was in a really minor（较小的） way. Thank you all. So, most of us in this room, and probably most of those watching at home, have wanted to take revenge（报仇） at one point or another. Revenge is something that lots of us can relate to. Most of us have thought about it, and we probably have some pretty strong ideas about what we think of revenge.

  Right now, I'm doing a PhD on the psychology（ 心理学） of revenge（报仇）, and when I started my PhD, I had some pretty fixed ideas in my head about revenge. I saw revenge purely（纯粹地） as a bad thing. It was evil（坏的）. It was immoral（不道德的）. It was animalistic. It caused harm（伤害）.

  It led to death and destruction（破坏）. And there was a really good reason why I thought this. The harms of revenge are very real. However, the more I've learned about the psychology of revenge, the more I've come to appreciate that it is so much more complex than just something evil, immoral, or animalistic only carried out by the very worst people in society. I mean, for one thing, we've already established（建立） that most of us in this room have wanted to take revenge（报仇）. Wanting revenge is common.

  It's normal. We're also fascinated by stories of revenge. Humans have written so many stories about revenge, dating（注…日期） back at least to the ancient Greeks. And Shakespeare（莎士比亚(1564-1616） later captured（捕获） the imaginations（想象） of people in 16th-century England with vivid plays about revenge（报仇）. And this fascination（魔力） with revenge（报仇） stories has not gone away. Think of blockbuster（轰动） films like Gladiator or Taken or TV shows like Game of Thrones.

  And I'm sure that all of you watching could come up with thousands more examples of revenge storylines in your own favorite films and TV shows. So our plays, films and TV shows all point to our fascination with revenge. But why is this? Why are we so fascinated（兴奋的） by revenge（报仇） and why do we all think about it so much? Well, evolutionary（进化的） psychologists（心理学家）, including Michael McCulloch, argued that our modern drive for revenge first evolved（发展） thousands of years ago. And this is going to come as a surprise to most of you, but they argue that our desire（愿望） for revenge（报仇） first evolved（发展） in order to promote cooperation between people.

  In other words, revenge evolved because it was useful for society. It served a purpose. It was a good thing. It was retaliation with reason.