[monkey_slap]

> Isn't a "3D Touch" a physically more demanding action than just a traditional tap? Why should the former be associated with a "quick peek" and the latter with a committed selection, rather than vice versa?

Physically, it is. You use more energy to activate it. But after using it for a while, the real benefit comes from browsing a list of stuff by only peeking and then backing out. You can consume a ton of thumbnails much, much faster since you don't have to reach the back button or swipe to go back. Instead, you just let go of the screen and it returns to where you were.

I actually really like your analogy of single-click and double-click. 3D touch sort of fills the single-click void.

Avoiding the trap is a real issue. 3D Touch should absolutely not be applied to every single element in every single interface. Challenge is how do you teach someone what can use a 3D Touch and what can't? Not sure we have the answer yet.

Full disclosure, I work on this at Instagram and wrote the post.