[dropcap]T[/dropcap]he hardest thing about upward mobility – the so-called American dream – is attaining it.

Perhaps the second hardest thing is this: Once you’ve risen from a hardscrabble upbringing and gained financial success, how do you pass the traits that helped get you there – hard work, accountability, passion and discipline – on to your children?

The natural inclination is to give them all the things you never had – and to shield them from the worries y...