[ghshephard]

To be clear (and I don't think you are implying this, I just want to be explicit) -I'm not suggesting that the adults impacted the development of the child's impulse control - I'm extrapolating from the cited paper towards a quite different conclusion. If their conclusion is accurate, that children are rational actors in the face of uncertainty (that is, if the children asses that future rewards are more or less likely to happen based on their assessment of the other adults in the children's life) - then what I'm suggesting is that the original study had a group of rational players, and what the scientists were measuring, wasn't impulse control of the children (which I'm suggesting might be innately consistent across the group, or at least not revealed in this study) - but instead, was identifying how reliable the guardians and adults in these children's life were. It stands to reason, that children growing up in stable households, would have a better chance of being prosperous in life, than those who grew up in unstable, unreliable homes.