Kagan (1976) revealed that as part of our six basics human needs, there exists at the same time both a need for certainty and another need for variety and uncertainty. This need for certainty comes from the fact that our brain likes to know what is going on and feel in control of its interactions by recognising patterns. Indeed, feeling more certain about the world around us, as though we understand something correctly and can therefore predict what will happen, leads to positive feelings of control and security. Moreover, when the craving for certainty is met, there is a sensation of reward. The ability to predict something and then obtain data that meets those predictions results in a positive feeling. That’s why some people enjoy the accomplishments they feel by cleaning their house, organising their files, solving problems, and so on: it gives them a positive feeling of certainty. In contrast, the brain reacts negatively towards uncertainty leading us to feel alert, anxious and uncomfortable.

The paradox is that this tension we feel when we are uncertain can also have a positive effect. It is often uncertainty that drives creativity and results in the variety and the element of spontaneity and surprise that we also crave as humans. Because of this, both certainty and uncertainty are human needs that have to exist in balance.

This theory has many important applications in marketing. In some cases, bringing certainty to your customers, reassuring them and giving them information is vital to ensure positive feelings are induced. Indeed, there are even entire industries that exist to resolve larger uncertainties because people are willing to pay in order to receive an increased level of certainty (for example, for expert advice on stock market predictions). On the other hand, sometimes inducing a certain level of uncertainty in your customers helps to encourage them to interact in the way you would like, motivating them to complete the desired action in order to regain a comfortable level of certainty.