My friend James Cathey sent me an eyebrow-raiser this morning: “Here is a sentence that stopped me in my tracks: "Robinson, who has a warm voice and is easy to laugh, has a way of setting the record straight …" (TIME: March 12, 2018, p. 50)"
Jim says he could never say "is easy to laugh" in any context that he can think of, and asks “What is going on here?”
I could never say that either, but then I was also surprised at some of the meanings Russian reflexives (and Polish, etc) can have — not only reflexive, reciprocal, and 'unaccusative' (the door opened, etc), but also transitives with missing object and a 'habitual' meaning — I heard it used standardly for 'that dog bites'.
So “easy to laugh” feels to me not totally impossible, and maybe related to the connection between 'These plates break easily' from a transitive and 'He laughs easily' from an intransitive. In the literature I've seen plenty of discussion of the 'break easily' cases and don't remember seeing any of the 'laugh easily' cases.
Maybe also relevant that “laughable” is one of the relatively few -able words formed from an intransitive? But the sense of “laughable” is very different, seems related to a transitive ‘laugh at’ sense, whereas this one is clearly based on intransitive ‘laugh’.