This shows everything, you can set a specific default (without changing the others) more simple with the example in the gist <a href="https://gist.github.com/joshuadavidnelson/931c351631219f7cb696#comment-1324687">comments</a>. See the defaults as listed in the (very useful) <a href="http://docs.garyjones.co.uk/genesis/2.0.0/source-class-Genesis_Admin_Settings.html#78">Genesis Docs</a> Gary Jones maintains.
Source: https://gist.github.com/joshuadavidnelson/931c351631219f7cb696