FBFriendPickerViewController not showing all friends

I am using FBFriendPickerViewController to display friends list for invite in my iOS app.

It only shows a list of friends who have the app installed. Why is this?

I also interact with the Facebook sdk directly in my application using the Graph API. Could this intervention? I open a session for this with permissions: public_profile, user_friends friends_games_activity, publish_actions.

The app is in development mode in the Facebook developer center.

Here is my code for showing the picker:

FBFriendPickerViewController *friendPickerController =
[[FBFriendPickerViewController alloc] init];
friendPickerController.title = @"Pick Friends";

// Load the friend data
[friendPickerController loadData];
// Show the picker modally
[friendPickerController presentModallyFromViewController:self animated:YES handler:nil];