Unless otherwise indicated, the code snippets you see below should be placed into your theme’s functions.php file.
Here is the code needed to remove the Author Box on single posts:
<?php
//* Do NOT include the opening php tag
//* Remove the author box on single posts XHTML Themes
remove_action( 'genesis_after_post', 'genesis_do_author_box_single' );
//* Remove the author box on single posts HTML5 Themes
remove_action( 'genesis_after_entry', 'genesis_do_author_box_single', 8 );
