What is cultural materialism?

Cultural materialism is a concept that is related to the
writer Marvin Harris.  It is a materialist approach that implies that culture emerges as
a product of things.  Consider this; when thinking about the things
that our society finds as having value.  People strive to attain things they value. 
Yet, the things that we have available to strive for set the stage for that which we
work for and desire.  A shovel has value to dig.  If a person is a farmer having the
need for a shovel would propel him into working to afford to own
one.

Harris developed his theories in two of his books
Cannibals and Kings written in 1977 and Cultural
Materialism written in 1979.  He explained the idea by stating that in India
the non-killing of cattle is a religious vessel but it is also an economic move that is
related to cultural needs that help stabilize their economy.