A small one would be good for a lap dog.
Ours is only a year but very light and doesn’t mind being picked up at all.
We had two mutt dogs. One black lab mix and a poodle mix. Both very smart and loyal dogs. Great watch dogs too. Years ago when my daughters were still in grade school they would grumble about getting out of bed for school. I would yell out”I’m sending the hounds in!” They would rush into the bedroom and start licking the kids faces till they got out of bed laughing with big smiles. Sadly our dogs have since gone over the rainbow bridge. We all still miss them.
So for my money,mutts are smartest!