I am still unsure of what you are asserting... are items 1-5 the 
cause of the lack of the ability to think laterally?  Is this 
asserted inability to think laterally the cause of the lack of 
*obvious* geniuses born since 1920 or so?  If so, are you also 
asserting that items 1-5 were not taught in school before 1920
or that perhaps they were taught, but at a later age (i presume
that everyone has learned these things for at least several 
hundred years, especially the *obvious* geniuses)?
There are some exercises in my daughters' second grade that i 
believe are meant to teach non-linear thinking.  For instance,
in one exercise they are given a piece of paper with a few marks 
on it.  From that, they are supposed to construct a picture that
they think no one else would.  Then they write a brief story
about the picture... (perhaps in the higher grades they may
do more analytical stuff).
ken
PS - i wanted to dispute your claim about *obvious* geniuses not
being born after about 1920 but was unable to come up with any
great examples... alot of those guys were older than i thought.
Of course, this may be just that once you have discovered the
fundamental underpinnings of the universe, what else can you
do but embellish them a bit... ;)
PPS - A xmas puzzle - can you connect all of the following x's 
with 4 straight lines  without lifting your pen from the paper?  
It can, of course, be done.
                x       x       x
                x       x       x
        
                x       x       x