You can configure most article options globally but not 'Page headings'. They are all turned on by default for Menu Item. There is not a method of setting this globally, so far.
Read Forum Thread for further information and indepth discussion about Tile, Browser page title and Page heading and the different places they are set.
There is a sneaky trick to avoid all that manual work. Run the following MySQL Statement on your joomla database
{code}update j25_menu set params = replace(params,'"show_page_heading":1','"show_page_heading":0');{/code}It will just do a search and replace on the params field in the j25_menu table. If your menu table has a different name, just replace it.