Apart from simply being fun to write, I reckon if everyone in the book talked the same and used the same body language, it would feel very flat. If the 'quirks' fit with with the character's personality and background, I find it can help them to feel like distinct people. As *LadyAnder said, I don't usually plan them. They just kind of come up.
Hmm, I can understand that. Well I like knowing my own characters more than just having their quirks just emerge. I know some might have it work well for some but I like knowing my characters a bit more before I start.
"Quirks" seem like a cheap way of achieving the illusion of depth, and I don't see how they make a character more "lovable", particularly when they have an air of artificiality. A quirk added for the sake of quirkiness is not interesting. A somewhat odd behavior that's merely one aspect of a complex, well-rounded, realistic character is another matter.
I agree, quirks shouldn't be added in for the sake of making someone more interesting. They should emerge from the character's attitude or something with a reason behind it. Most people have a way of doing things that is different than anyone else.
i take things ive seen from my own life, or things ive done myself. I grew up on the south east asian countryside, beside a strange little farming community, and i have many fond memories of my crazy family and neighbours... this kid i used to know once went to the city with his dad and was SUPER scared of elevators, like, it left him traumatized. So i used that as a quirk in one of my OC's
I don't tend to think up quirks beforehand, I tend to work out basic personality and find quirks during the writing, if the characters have them. For me that seems to make them more natural, as they seem to develop from personality, history and environment, rather than from a desire to add a quirk.
I should add, in addition to my last post, that quirks are by no means but but they are not the great secret to good character that some writers think they are. As Saintartaud has said, this topic has come up before and people have glorified quirks and their quirky characters - going so far to assume that obnoxious behaviour is going to be fun to read about.
It depends a lot on the story you're writing and the tone of your work. More exaggerated, flamboyant quirks are appropriate in a comedy, for example. In noir? Not so much. But as a general rule, a unique and unusual mannerism should have a reason and say something more profound about the character other than "He is different".
And don't go on and on about it like you're trying to say "Look, reader, look! I made my character interesting!" Also, don't make it their every other action because then you just look like you're being lazy, too.
This subject has come up in forum before, and I agree with what's already been said. Quirks can add to the richness of a character and story, but a quirk alone doesn't add more depth to a characterization. The only way it could is if the quirk connected to something very deep in the character that changed our understanding or ignites a change in the character. A quirk is also pointless if it adds nothing to the story. Like, a character being obsessed with cheese might be quite funny, but it would only deeply matter if that obsession compelled the story or motivated the character. This isn't to say little quirky details about a character can't add texture and interest, it's just that the whole picture is often more important.
To throw out an example from my own work, I have a character who writes letters in purple ink and likes to wear the color a lot when he can. Specifically, he has a purple opera coat that he wears around town. It's a fairly minor affectation that really has no impact on the story, but it does reflect something of who he is, i.e. someone who goes for aesthetic affectations because he lives his life as art.
See it is pieces like you mention that I feel are the best to make a character just more than a face or some cliche' personality. Though a single color that permeates a characters life could be misunderstood as something else. The odd obsession with cheese, well there was quite a lot of story and history behind that from what I understood about the character.
There can also be degrees of quirks, like the one you referenced or smaller ones. Like how they shakes hands, might give evidence of their manners or upbringing. I'm not saying quirks without reason are good or should even be used just that various quarks can add to a character and better explain them without shoving those explanations in the readers face.