Modified to display full content for posts in all categories.

full-content-archives-genesis.php

<?php
// Do not copy opening PHP tag above

// Force content archves ti display full post content with no featured image
add_action( 'genesis_before_loop', 'wsm_full_content_categories' );
function wsm_full_content_categories() {
	if ( is_category() ) {
		add_filter( 'genesis_pre_get_option_content_archive_thumbnail', 'wsm_no_post_image' );
		add_filter( 'genesis_pre_get_option_content_archive', 'wsm_do_full_content' );
		add_filter( 'genesis_pre_get_option_content_archive_limit', 'wsm_no_content_limit' );
	}
}

function wsm_no_post_image() {
	return '0';
}

function wsm_do_full_content() {
	return 'full';
}

function wsm_no_content_limit() {
	return '0';
}