Psychology in Everyday Life

Exploring the science behind how we think, feel and behave.

Why Knowing What Is Good for Us Isn't Always Enough

Most of us already know quite a lot about how to look after our health. We know regular physical activity is good for us, that sleep matters, that smoking carries health risks, and that a reasonably balanced diet is probably better than living entirely on biscuits. The interesting question, then, is not always what we should do, but why we do not always do it.

This is one of the central questions in health psychology, a branch of psychology concerned with how our thoughts, emotions, habits, social circumstances and environment influence our physical health and health-related behaviour. Rather than simply asking what people know about health, health psychologists explore the psychological factors that influence whether people actually make healthy choices.

One of the key ideas in health psychology is the intention-behaviour gap. We may genuinely intend to exercise more, eat more healthily or improve our sleep, but intentions do not always translate into action. This helps explain why behaviour change can be challenging, even when people are highly motivated and understand the benefits of making healthier choices.

A useful framework for understanding health behaviour is the COM-B model, developed by Susan Michie and colleagues. The model suggests that behaviour depends on three broad factors: capability, opportunity and motivation. In other words, a person may want to make a change, but they also need the knowledge, skills and confidence to do it, alongside an environment that makes the behaviour realistic and achievable.

This helps explain why telling somebody to "try harder" is rarely a particularly effective strategy. Someone may be highly motivated to become more active but have limited time, caring responsibilities, chronic pain, financial pressures or few local opportunities to exercise. In these cases, motivation may not be the main barrier to change.

Confidence is also important. Psychologist Albert Bandura used the term self-efficacy to describe an individual's belief in their ability to carry out a particular behaviour successfully. Someone may strongly believe that exercise is beneficial while also thinking, "I am terrible at exercise" or "I never stick to routines." Research suggests that self-efficacy plays an important role in both starting and maintaining healthy behaviours. This is one reason why small, achievable goals are often more effective than ambitious plans. Success provides evidence that change is possible.

Another well-established concept is the use of implementation intentions, sometimes called "if-then" plans. Saying "I am going to exercise more" is vague, whereas "If I finish work at 5.30pm on Tuesday, I will go for a twenty-minute walk" connects a specific situation with a specific action. These detailed plans can help bridge the gap between intention and behaviour by reducing the need to make a fresh decision when the moment arrives.

Habit formation adds another layer to our understanding of health behaviour. Many everyday actions happen automatically rather than through conscious decision-making. We make coffee after getting up, check our phones when we hear a notification or reach for the same snack at the same time each day. Repeated behaviour in a stable context can gradually become a habit. This helps explain why unhealthy routines can be difficult to break, but it also shows how healthier habits can become easier over time.

Stress can complicate things further. When people are tired, anxious or overwhelmed, immediate comfort may become more appealing than behaviours whose benefits will be seen in the future. As a result, stress can influence motivation, decision-making and health behaviour in complex ways.

Health psychology encourages us to ask better questions. Do people believe they can succeed? Do they have the opportunity to make the change? Are existing habits working against them? Could a more specific plan help? What role do stress, confidence and environment play?

Seen in this way, health behaviour becomes less about judging people for making "bad choices" and more about understanding the psychological processes that shape those choices. Perhaps the most useful question is not, "Why don't people just do what is good for them?" but rather, "What would make the healthier behaviour easier to do?"

That is where health psychology becomes particularly useful.