Re: OT from your post but...

I disagree. First off, legally that is still defined as incest because the adult has the role of parent in the home. Secondly (and more importantly), I'm looking at it from the child's point-of-view, and to the child the adult caretaker(s) in his or her home is generally viewed as a relation, regardless of actual blood connection.

Good point, about the child's point of view.

Pinker actually took pains to separate coercive incest from noncoercive incest in his book. As he goes on to say (from the paragraph I quoted): "Most of the rest are between fathers and daughters, and virtually all are coerced by the father. Some are between girls and other older male relatives, also mostly coerced."

I doubt his research is unbiased. I'll have to look at the book myself. To see his sources. Mostly coerced? Doubt it. I need to see his sources.