You’ve probably heard that it takes 21 days to form a habit, but this idea comes from a misinterpretation of Dr. Maxwell Maltz's work. In his 1960 book Psycho-Cybernetics, Maltz observed that it took patients about 21 days to adjust to changes such as amputations or cosmetic surgery. Over time, this concept was generalized and simplified, leading to the "21-day rule" for habit formation. However, this is not accurate for most people.

2. The 66-Day Average

A more reliable study conducted by Dr. Phillippa Lally and her team at University College London found that, on average, it takes 66 days to form a habit. The study, which followed 96 participants over a 12-week period, showed that the time it took to form a habit varied widely—from 18 days to 254 days—depending on the individual and the complexity of the habit.

For example:

• Simple habits like drinking a glass of water in the morning were formed more quickly.
• More complex habits like exercising regularly took much longer to become automatic.

3. Factors That Affect Habit Formation

Several factors influence how long it takes to form a habit:

• Complexity of the habit: Simple habits (e.g., drinking water) tend to take less time than complex ones (e.g., learning to play an instrument).
• Consistency: The more consistently you repeat the habit, the quicker it forms. Missing days or being inconsistent can slow down the process.
• Environment: A supportive environment can help reinforce habits. For instance, if your goal is to eat healthier, surrounding yourself with nutritious food makes the habit easier to form.
• Personal motivation: If you are highly motivated and committed to a habit, you’re more likely to stick with it long enough to make it automatic.

4. The "Automaticity" Threshold

The goal of habit formation is to reach the point where the behavior becomes automatic—what researchers call "automaticity." This means you engage in the habit without needing much thought or effort. The 66-day average suggests that, for most habits, about two months of consistent repetition is needed for them to feel automatic.

5. Don’t Stress About Perfection

The key takeaway is that forming a habit isn’t about hitting an exact number of days. It’s about being consistent and patient. It’s okay to miss a day or two—Lally’s research found that occasional slips didn’t significantly affect the process as long as people resumed their habit soon after