Is the hatch supposed to open automatically when the lock is disengaged?

I keep reading about the hatch struts and was wondering how they are "supposed" to work.

My hatch required a decent lift to open but it will stay open on its own. Other cars I've owned pretty much will lift the door/hatch on its own and was wondering how the cayenne hatch is designed. Thanks.

 

it's an option to have the hatch open automatically. Mine didn't come with it.