No proof of that.
It's more because of the upbringing, people were found to be less likely to romantically pursue people they lived with as children in the kibbutz experiments. It's called Westermarck effect, you aren't usually attracted to people you grew up as a child with, not because they are related to you.
Social stigma also probably plays some role in that. If incest was a widely accepted practice, more people would engage in it.
If you didn't know your sister and randomly met her, nothing would stop you from being attracted to her. In fact, close realatives have gotten into relations without knowing that they are related. There's no magic "hardwires" stopping anyone. You can't magically tell how close genetically someone is to you.