The Big 5 and creating a believable character

There are 5 central character traits in movies. These character traits are universally known to be true for all characters in movies.

1. Openness-being creative, imaginative and curious. 
2. Conscientiousness-being thorough, focused and organised. Much like Monica from friends.
3. Extraversion - being talkative, energetic and social.
4. Agreeableness-being helpful, selfless and kind.
5. Neuroticism-being anxious worries and easily frustrated. 

Magnification is a good way to create a believable character. Its a way of making the ordinary extraordinary and you do this by taking one of your characters traits and making them extreme.
For example the hulks strength. But creating a believable character isn't the same as creating a realistic character. This means that you have the freedom to make your character's trait as extreme or wacky as you like.