Yep. It's more a case of 'conditioning' rather then 'training' at at higher intelligence level.

Mine will sit on my lap for no more then 15 minutes or so, but then it's cold here and his place is the warmest place in the house! :-(

Having said that, my 3.5 year old male ball seems to behave differently depending on whose handling him. With me, he's always on the go. When my wife holds him, he's content to just sit there with her. When my daughter holds him, he stretches out and rests his head on her shoulder like a baby!

What makes them so fascinating, I guess!