I BECAME a psychologist because I was puzzled by how hard it is to understand people. Our reasoning is made of complicated mental processes that help us understand ourselves and the others.
But more often than not we are not aware of, or are wrong about, why we act the way we do. Because of this, we are tempted to believe that psychology equals common sense.
But psychology is a science, and it obeys scientific rules in explaining human behaviour just like any other science. To know a little bit more psychology than the average individual means to know that what seems obvious is often not the real reason behind someone's behaviour.
My research tries to answer questions like why do we often not act as we know we should? and what can help us to be more rational? There are many situations in which knowing these answers is paramount - from how to stay healthy and motivated, to how we relate to others, and whether we get involved in societal issues.
In my teaching I show my students that healthy behaviour, for instance, is not just something strong-willed people do. Instead, it is a mixture of many influences, some of which don't easily come to mind - access to resources, social support, how the environment is structured around us, or something as trivial as how much time we have to cook more healthily.
A common "judgment bias" (or error) is to think that we need less time than we actually do, to realise something.
My research shows that if we think about the effort we need to put into making a deadline, we will plan for it better. In other research about what helps us lead healthier lives we found that people often take their health - and many other values - for granted. …