flightoffancy writes:

I don't deny those facts; but the greater the curve of the wing the more
the air pushes down behind the wing.

If that were so, then an airfoil with a half-circle for a cross-section would
produce enormous lift. In fact, this isn't the case.

Notice the smoke flow in the photo I link to below:

http://www.aa.washington.edu/uwal/uw.../tech%20guide%
20pics/smokeflowvis.gif

Granted it's at a high AoA. I'm just concluding what I have read about
wing curvature is consistent with what I see the smoke doing in the
picture.

But it would do the same thing with a flat airfoil.

The explanation of why wings with greater curve bend the air down more I
wouldn't want to say without studying aerodynamics more thoroughly.

A greater curve does not increase downwash, unless it also changes the
effective angle of attack. AOA is everything.