Get author role name

Take a look at Justin Tadlock’s code:

http://wordpress.org/support/topic/get-a-users-role-by-user-id?replies=20#post-1363118

Not sure about author pages but in a loop that would be (ugly modification below)

$user = new WP_User( $post->post_author );

if ( !empty( $user->roles ) && is_array( $user->roles ) ) {
        foreach ( $user->roles as $role )
                echo $role;
}

Once you have the $role output, you can clean it up and display Editor, Contributor, Cook, etc.