submodule: --recurse-submodules vs. submodule.recurse=true

I'm using git 2.14.1 on cygwin.

Using --recurse-submodules, I can do 'git pull' and the submodules both get fetched and merged automatically. I was under the impression that setting submodule.recurse to true would have the same affect, without needing to write --recurse-submodules every time. But the docs seems a bit vague, and I don't understand the git code.

Is there a way to config git pull to automatcially do a "--recurse-submodules" ?

Thanks, Magnus