Large-scale surveys are useful but if we are serious about changing behaviours, we must use every tool to understand human complexity.
Recent advances in behavioural economics, cognitive neuroscience, network theory and social psychology more generally have overturned our common sense understanding of human behaviour. The rational, autonomous, self-aware agent acting in his own self-interest according to static preferences has faded as we realise that behaviour is largely irrational, unconscious and driven by external contexts. Ladies and gentleman, Homo economicus has left the building.