Correlation and causation: meditations on violence

XKCD looks at causation and correlation

XKCD looks at causation and correlation

With XKCD’s comic firmly in mind, I considered the news today. Constance Holden with the ScienceNOW Daily News over at Science Magazine drew my attention to an article linking violence to childhood sugar consumption. The telling quote is this:

Although lower education levels correlated with daily sweet-eating, the connection with violence remained significant even when the researchers controlled for factors such as family circumstances, parental attitudes, and IQ. “Try as I did, I couldn’t get rid of the sweets-violence connection,” says Morris.

So… it may be that highly sugared children (sugartots?) are made more violent by sugar… or it could be that violent people are drawn to sugar as children… the candy manufacturers may be drugging children to reduce their impulse control… or kids whose without parents failed to help them learn impulse control lack impulse control in adulthood… it’s all very complicated.