I notice that my "lazy" villagers apparently didn't get enough of the right kind of skills when the Chief was teaching them. (If we're talking about the ones who laze around the firepit, that is.) I generally teach them to fish. You know what they say - give a man a fish, and you feed him for a day. Teach a man to fish, and you can generally get rid of him for an entire weekend!
On the other hand, if you're talking about the occasional villager who just WON'T learn - I teach them one thing, because that's all I have the patience for.
I do notice that most of my VV3 villagers have ADHD. "I'm going to research. No, I think I'll go watch the fish instead. Nope, changed my mind again, I'll go help on the building project. Nope, relaxing in the bath... at the beach... getting a drink of water..." etc. Can't hardly keep them in one place.
And when I've left the game running and come back - everyone is either gathered around the food bin, or holding a village meeting in the ocean. What's up with that??