How do I detected collision/overlap between same object

How do I detect a collision / overlap between instances of the same object without resorting to families?

instance on collision with instance, and instance is overlapping instance do not seem to trigger.

attached capx demonstrates.

I am against using families, because if I need to put each instance in its own family and test for it, I may as well use separate objects.

Um, what instances are you trying to collide in your .capx? I was able to play pong with myself successfully by tabbing quickly.

Here's a super-bare .capx where you can drag around two squares, which are both the same object.

When they collide, the red one always rotates, and the pink one always moves.

And, while they're overlapping, the colors change just slightly.

Apologies, I uploaded the wrong file, doh, but looking at your capx I think I understand the problem, because I was limiting the selection to the item being dragged, it is a SOL list of one, and hence cannot collide.

Thank you for the enlightenment.