Stories of old taught us that we should love heroes and hate villains. Yet that is no longer true. Baddies are becoming more complex, relatable, and - as a result - more popular.
In the past, this was not so. In the mid-1900's, Hollywood had to follow the Hays Code, which tried to ensure the bad guys never seemed too cool, for fear that the audience would try to be like their favourite baddie.
The Toy Story trilogy is a good reflection of how film audiences have changed attitudes towards the villain. Sid in 1995's Toy Story had little reason to be so cruel, so we were pleased when the toys taught him a lesson. The toy Stinky Pete in 1999's Toy Story 2 wanted freedom from storage, we disliked him but we understood his motivation. By the time of 2010's Toy Story 3 we had Lotso, who became nasty after his owner left him behind and replaced him without a second thought. Lotso was mean, so we were glad our heroes prevailed, but we felt sorry for him, too.
So, why do we now like our villains so complicated?
"I had wings once … but they were stolen from me," says Maleficent in the trailer for the upcoming Disney release of the same name. This suggests she was wronged in the past, and not as unjustifiably evil as she seemed in 1959's Sleeping Beauty.
And Maleficent's isn't the first villainous origin story we've seen of late.
Last year's Oz the Great and Powerful saw how deceit transformed Mila Kunis' character from the kind Theodora to the vengeful Wicked Witch of the West, the green-faced villain of the 1939 The Wizard of Oz. Broadway told its own version of the witch's story, in the hit musical Wicked.
Marvel Studios has also capitalised on the recent popularity of villains. Tom Hiddleston has played Norse god Loki in three films, whose past as an abandoned orphan and less favoured son drives him to turn to the dark side.
"A lot of villains have traumatising past experiences," says Dr Chen Zhansheng, from the department of psychology at HKU. "People can easily sympathise with them."
So, yes, villains are bad, but when their motivations are so very human, we hope they find redemption. This translates to a hope that we may redeem ourselves when we make a mistake. And because we're so used to recognising our flaws rather than our virtues, it's just easier to identify with the flawed baddie, and so to like them.
Then there are villains who are just so cool, we can't help but want to be them. "Rooting for the Bad Guy: Psychological Perspectives", in the 2012 academic journal Studies in Popular Culture, suggests we live vicariously through villains.
It adds that we're conditioned to think of heroes as attractive and villains as ugly. Most classic Disney villains, like Ursula in The Little Mermaid and Jafar in Aladdin, and Shakespearean villains like Richard III, described as a "poisonous bunch-back'd toad", back up that theory. But even in her first appearance in Sleeping Beauty, Maleficent was both wicked and beautiful.
She's so iconic, MAC Cosmetics is releasing a Maleficent collection to coincide with the release of the film, which stars Angelina Jolie. With "beautiful" people like Jolie, Kunis and Hiddleston playing the villains, it's no wonder we're as sympathetic towards them as we are to the heroes.
In the end, whether you love villains or hate them, in films at least, they exude qualities we would all like to possess: good looks, intelligence, wit, humour, leadership, confidence.
There will always be a debate about whether glamorous villains are a bad influence on society. Fans of the bad guys though, would probably say we understand how reality is different to fiction. So as The Joker would say: "Why so serious?"
Check out more on Maleficent on page 12