Don, I think the graph shows the SAT scores from low to high (L to R).

Below each score is a list of musical styles and groups that people (according to the Facebook Stat Pages) with that SAT score liked to listen to.
Some of course overlap or spread into the next score column.

Of course the sampling is only for people on Facebook who shared their musical preferences so is probably skewed in favor of the younger segment of the population.

My opinion is that we are all born with a certain audio sensitivity or preference, maybe shaped genetically or even in the womb.
To some, certain sounds are soothing, to others, the same sounds may be a fingernail on a chalkboard.

Starting with this base our musical tastes then begin to form, influenced by some or all of the influences stated above.
Bottom line is some people may never like certain types of music because they conflict with their "inner harmonic".

Hey maybe I could write a New Age philosophy book! Would come with a free pair of hip waders.

Check out these quotes about music and taste, pretty funny.

http://www.famousquotesandauthors.com/topics/music_quotes.html

Enjoy,
Carkins