A new study by researchers at the University of Surrey, the University of South Carolina, and Central Queensland University suggests that much of what we do every day is guided by habits rather than conscious decisions. Published in Psychology & Health, the study found that about two-thirds of daily behaviors are automatic, running on “autopilot” because they have become routine.

Habits develop when people repeatedly respond to familiar situations in the same way. Over time, the brain associates certain situations or stimuli with certain actions. When these stimuli occur, the associated behavior can kick in automatically and without conscious thought. The researchers also found that 46% of behaviors were both habitual and consistent with people’s intentions. This suggests that people often develop routines that support their goals, while gradually weakening habits that conflict with their goals.

Tracking Habits in Real Time

To better understand how habits work in everyday life, the research team used a method that tracked behaviors in real time. Previous studies have attempted to estimate how often habits influence behavior, but this approach aimed to observe them in real time.

The international team recruited 105 participants from the United Kingdom and Australia. For one week, participants received six random prompts on their cell phones each day. Each time, they were asked to describe what they were doing at that moment and to indicate whether the action was triggered by a habit or performed consciously. The results showed that 65% of daily behaviors were initiated habitually. In other words, most actions were triggered by routine impulses rather than conscious decisions.

Professor Benjamin Gardner, professor of psychology at the University of Surrey and co-author of the study, explained: “Our research shows that although people consciously want to do something, the actual initiation and execution of that behavior often occurs without thinking and is controlled by unconscious habits. This suggests that ‘good’ habits can be an effective means of achieving our goals.

“For people who want to break their bad habits, it’s not enough to simply tell them to ‘try harder’. To bring about lasting change, we need to incorporate strategies that help people recognize and break their unwanted habits and, ideally, develop new positive habits in their place.”

Why Habits are Important for Health and Behavioral Change

The findings could have important implications for public health programs and lifestyle change interventions. According to the researchers, efforts aimed at promoting behaviors such as regular exercise or healthier eating should focus on helping people establish consistent habits.

For example, if someone wants to exercise more, it can be difficult if they only work out occasionally. It would be better to link exercise to a fixed time of day. This could mean exercising at a specific time or immediately after a regular activity, such as after work, and doing so repeatedly in that situation.

A similar strategy is needed to break unhealthy habits. For example, if someone wants to quit smoking, motivation alone may not be enough. More effective approaches include interrupting the triggers for the habit (e.g., avoiding places where you used to smoke) and creating replacement routines (e.g., chewing gum after meals instead of smoking a cigarette).

Dr. Amanda Rebar, associate professor at the University of South Carolina and lead author of the study, said, “People like to think of themselves as rational decision-makers who carefully consider what they do before they do it. However, many of our repetitive behaviors are performed with minimal advance planning and instead arise automatically from habit.”

The Role of Habit in Building Healthier Routines

The circadian rhythm plays a central role in establishing and stabilizing habits and, therefore, in developing healthier routines. The circadian rhythm is the human body’s internal biological clock, which follows an approximately 24-hour cycle and controls numerous physical processes, including sleep-wake rhythms, hormone production, body temperature, metabolism, and alertness. These biological fluctuations influence when we are particularly productive, tired, or motivated.

Habits often become particularly stable when they coincide with these natural biological rhythms. When certain activities take place regularly at the same time of day, the circadian rhythm can act as a temporal “anchor” that automatically triggers behavior. For example, going to bed at the same time every night can condition the body to release more of the sleep hormone melatonin in the evening. Similarly, a fixed mealtime can prepare the metabolism to process food efficiently. In this way, the internal clock supports the development of routines by linking specific times of the day with specific actions.

In addition, the circadian rhythm also influences the likelihood that habits will be maintained in the long term. Behaviors that run counter to the biological clock—such as working late at night or irregular sleeping hours—can disrupt the rhythm and thus make it more difficult to develop stable habits. When routines coincide with natural phases of energy and rest, however, they feel less strenuous and can more easily transition into the “autopilot mode” mentioned in the study. The circadian rhythm thus acts as a biological basis for habits: it structures the daily routine, facilitates the repetition of certain actions over time, and thereby supports the automation of health-promoting behaviors such as regular sleep times, meals, or periods of exercise.

Dr. Grace Vincent, sleep scientist and associate professor at Central Queensland University and co-author of the study, said the findings offer encouraging insights for people who want to improve their health and daily routines. “Our study shows that two-thirds of daily actions are determined by habits and that in most cases these habits are consistent with our intentions. This means that when we set out to adopt a positive habit, whether it’s related to better sleep hygiene, nutrition, or general improvements in well-being, we can rely on an internal ‘autopilot’ to take over these habits and help us maintain them. “Unfortunately, not all habits are the same. Exercise was the exception in our results, as it was often triggered by habit but, compared to other behaviors, was less likely to be performed purely ‘on autopilot’.”