Nested Permissions Heirarchy in SharePoint 2010

Question

I have not found a clear answer to the following question -
For any sub site, list, library, or other SharePoint object with non-inherited unique permissions, what happens if a specific user is individually listed with their own ID with , say, for example Contribute permission level, but the same user is part of
a SharePoint group that is at a READ permission level to the object in question? 
Would SharePoint give the specific user Contribute level access, or lock them down to READ access due to the user's group membership? - Why?
Can anyone direct me to a graphic flowchart of how SharePoint parses such permission level conflicts?

Answer 1

This is where my confusion is.
If a user is granted a specific user permission to an item of Contribute, but, because that same user is a member of a SharePoint group that has only READ permission to the same item, which applies? - Your note above seems to indicate both.   That
makes no sense to me. - Both can't really apply as the group READ permission to the item question, through the user's membership in that SharePoint group would tend to block the user specific Contribute permission. How can a user have both a READ and a Contribute
permission to the same item? A reader typically isn't allowed to contribute.....
Another way of looking at this is maybe, because of individual permissions and group permissions, and multiple group memberships being possible, the way to look at it is that a single user may have " multiple doors " into the same room with the
item being accessed and each is a valid doorway in it's own right and has no impact on any of the other doorways to the room.  Does that work, conceptually?
But looking at it this way tells me that a group permission lockdown to a piece of data can be almost invisibly negated by membership in a higher access permission group or direct access to the same data at a higher level.  That's a problem and difficult
to detect without constantly auditing group memberships to heavily trafficked data.