Load bearing confusion

This is an illustration from InterNACHI of load bearing walls.
Question: Why is the center wall on the second story not a load bearing wall but that same wall on the 1st floor a load bearing?
(I understand I asked that with the “1st” floor)
Also, if there was multiple floors i.e. 3 or 4, would the 1st floor still only be considered the load bearing walls?

Because the truss spans from eave wall to eave wall on the second story and the below floor carries part of the floor load, of that floor, on the middle wall.



^^^^^What Larry said^^^^^

Some engineered trusses rely on interior load bearing walls to reduce design cost for long or unusual truss configurations. However in this post as shown the answers given are correct. Just don’t assume this is always the case.

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So my question is, if the picture is a 3 or 4 story building, would all load bearing walls in the center be on every floor except the top?

In theory, yes.

The center walls supporting a flooring system above will likely be load bearing unless the floor joist system is specifically engineered to clear span to the exterior load bearing walls.

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Awesome, thanks guys.