Learn English – Word which means – “decreases the beauty “

Orthogonal

Counterintuitively, the teenager's grandmother uses text messaging much more than he does.

counterintuitive - contrary to what intuition or common sense [or expectation] would indicate.

Potential differences between counterintuitive and unexpected are...

1: Normally, only "facts" or "conclusions" (not "events") are described as counterintuitive.

2: Normally, counterintuitive implies that you actually expect an "opposite" scenario to be true.

3: Something can be unexpected even if you hadn't previously given any thought to the possibility of it happening. Thus, the doorbell can ring unexpectedly late at night, but probably not counterintuitively.