'Star Wars' Vs 'Star Trek' was once a heated rivalry, not between franchises but definitely between fans.

Existing both on television and the silver screen but largely at different times, the debate is more about which element of science fiction is better - the science (a key aspect of 'Star Trek') or the fiction (the fantasy element of 'Star Wars').

It's not as heated as it once was but the percieved rivalry meant J.J. Abrams' appointment as 'Star Wars: Episode 7' director having directed two 'Star Trek' films was a controversial decision to some.

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At Wondercon Anaheim in California on Friday a set of four experts including four psychologists debated which was better, running down four topics.

This debate first looked at which series had the better story, which boiled down to the strengh and character arcs of each of the series' two most famous villains - the genetically engineered Khan and the once-good Darth Vader.

"Vader is someone you can probably diagnose with borderline personality disorder," said clinical psychologist Dr. Ali Mattu. "In fact, the American Psychological Association hosted a talk on this very topic in 2007. Whereas Khan is the most dangerous thing in social psychology when you dehumanize people. You get things like the eugenics wars and the Nazis."

"Khan had a later life transformation," said Larry Nemecek, author of 'Star Trek: The Next Generation Companion.' "When we first met him in the 'Star Trek' television series, he was a villain. But when he comes back in the second film ['Wrath of Kahn'], his wife has been killed and his adopted planet ruined."

Dr. Andrea Letamendi, a psychologist, fought for the side of Vader, claiming his story to be better because of its complexity. "George Lucas really has an understanding of what makes evil," she said. "There is a sophistication of what makes risk, loss and antisocial behavior. We are reminded that humans are complex."

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Next up they looked at the strength and resilience of the characters, with both sets of characters' moral choices and the mistakes they make along the way to a conclusion. "The main point is not win or lose but how you went down," Nemecek said.

This is probably looking a lot like concentrated geek on a page, and it is, but it's about to get geekier - they then talked about robots and how the characters interacted with them.

Finally came round 4, "The Test", in which it was debated which series had a greater journey for its characters.

"It's an inspirational, motivational story that goes to the core of what it means to experience self-actualization and self-individualization," Letamendi said of 'Star Wars.' "It's actually what psychologists consider to be the most advanced state of being. And they have bad-ass costumes."

In defence of 'Star Trek' Mattu said, "What happened to me when I saw 'Star Trek' was that I could see myself there. It was a future we could see, a mirror into ourselves. How with empathy, science and knowledge we can grow, improve as a society and overcome."

Mattu finished the talk by saying, "Here's how we all win: We all have J.J. Abrams now."