The two are inextricably combined. It has been said that "language predetermines what we see in the world around us". Consequently, it - to a large extent - actually 'creates' culture. If you really want an in-depth answer to this, click http://anthro.palomar.edu/language/default.htm
and a link will take you to an excellent website. Once there, click especially on the heading 'Language and thought processes', though the other sections are equally fascinating.