Question: I'm looking for a word used in interaction design and probably in other fields as well.

It's used for the following purpose:

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> If a door has one handle which is a flat surface and another hanlde which is a bar then the bar has a ****\_*\_\_*** for being pulled, and the flat surface has a ****\_*\_\_*** for being pushed. 
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What is this word?

It would be used to describe that an object complies with its "desire" or not to be able to make the user experience as intuitive as possible.

Answer: 
The usual word for this in the computer trade is an *[affordance](http://dictionary.reference.com/browse/affordance)*:-

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> A visual clue to the function of an object.
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See also [here](http://en.wikipedia.org/wiki/Affordance).
I'd use "[penchant](http://dictionary.reference.com/browse/penchant)" (noun.
a strong inclination, taste, or liking for something: a penchant for outdoor sports.)
or "[affinity](http://dictionary.reference.com/browse/affinity)" (noun 1. a natural liking for or attraction to a person, thing, idea, etc. 2. a person, thing, idea, etc., for which such a natural liking or attraction is felt.).