A video shows a person’s brother placing his mug in the dishwasher, his jacket never touching the back of the chair. While others leave keys, chargers, and mail lying around, he closes the drawer behind him without even thinking about it. People often label such behavior as "rigid" or "perfectionist." However, this reflex is less about an obsession with order and more about a particular relationship with habits and mental load. The Impact of Disorder American psychologists Darby Saxbe and Rena Repetti measured the effect of disorder on the body. In their 2010 study, 30 couples kept a journal of their moods and provided saliva samples. Participants also allowed researchers to visit their homes, and the researchers noted the words they used: "in disarray," "incomplete," or conversely, "restful." The results, published in the journal Personality and Social Psychology Bulletin, have circulated widely since. Women who described their interiors as cluttered or filled with unfinished projects showed a flatter cortisol curve throughout the day, a profile associated with chronic stress. Those who described their homes as peaceful saw their stress hormone levels drop normally in the evening. Depressive mood was also more pronounced in homes described as cluttered. Among men, no such link appeared. However, caution is advised: the sample size was small, and the study establishes a correlation, not a causation. It suggests, however, that a stray object acts as a reminder of a task to be done, and the brain notices it even when one is not thinking about it. Putting things away immediately cuts off this reminder before it becomes established. Habit, or the Art of Not Thinking About It The question remains: why do some people manage this effortlessly? Psychologist Wendy Wood, from the University of Southern California, has a theory. In a study published in 2002 in the Journal of Personality and Social Psychology, her teams asked students to note every hour what they were doing, thinking, and feeling. Between 35% and 43% of their actions, according to the two studies, were habitual: repeated actions almost every day in the same place. These are also the actions that cost the least. When participants acted out of habit, they thought about other things and reported less stress than when performing new actions. Those who put things away immediately do not necessarily have more willpower. For them, the action has become associated with a context (placing the mug, going to the sink) until it becomes automatic. They are not forcing themselves; they are saving mental energy. And this difference does not stem from a fixed character: a habit is built.