Guichet: How to avoid the traps set by your brain

We think we're totally free in our consumer choices, our political opinions, our tastes, in fact, but that's not quite the case. Marketers, but also politicians, use what are known as cognitive biases to sell their soup or their arguments, and quite often, we buy without realizing it! How can we identify these biases, how can we counter these errors of reasoning so that we don't get fooled again?