IF YOU made a New Year’s resolution and are already having trouble sticking to it, don’t be too hard on yourself. It is not just a question of self will. Recent research shows that our behaviours and habits are more strongly influenced by friends and relatives than we might imagine. Furthermore, it seems that behaviours, ill-health and even moods pass through friendship networks across several degrees of separation, and we are almost bound to “catch” them (see “Three degrees of contagion”).
These findings have two important implications. The first is for public health. Governments tend to tackle issues such…
