How to show content for posts of a specific category only
You can use the in_category function to test if the current post in the loop is in the specific category you want to display full content for. For example if ( in_category( ‘my_category’) ) : the_content(); else : the_excerpt(); endif; For more information on the in_category function see the WordPress codex at: http://codex.wordpress.org/Function_Reference/in_category