I thought any time I was playing with my kids, as opposed to kids playing together, was a good opportunity to have many teachable moments. From the time I played any game with them, taking turns, no cheating, and basic decency towards all others in the games were requirements and conditions of my playing with them.
I would think any child wanting to play a board game is old enough to start learning such things. I also would't think of this as hot housing but rather as parenting. Aren't parents supposed to teach their kids how to interact with other kids?
