A new study from Johns Hopkins University suggests that deeply ingrained habits may form much faster than previously believed, challenging the long-standing view that habits develop only through gradual repetition over extended periods.
Published in the journal Nature Communications, the research indicates that a specific brain region may play a key role in the rapid transition from goal-directed behavior to automatic habits, a finding that could eventually help scientists develop new ways to change persistent or unhealthy behaviors.
Many everyday actions begin as conscious choices—such as checking phone notifications or eating an evening snack—but eventually become almost automatic. For more than a century, scientists believed this shift occurred gradually through repeated reinforcement.
Lead researcher Kishore Kuchibhotla, a neuroscientist who studies learning in humans and animals, said the traditional theory was based largely on the methods used to study habit formation rather than on direct observation of the process itself.
A New Way to Study Habits
Conventional experiments typically rely on rewarding animals for completing tasks and testing them only at fixed stages of learning. This approach made it difficult to determine exactly when a behavior became habitual.
To address this limitation, the researchers developed a new experimental model designed to better reflect real-life motivation. Instead of rewarding thirsty animals, they gave mice continuous access to sour water in their cages while allowing them to receive plain water—which they preferred—by responding to a specific sound.
Initially, the mice responded only when they wanted the preferred water, demonstrating goal-directed behavior. At a certain point, however, their behavior changed abruptly: they responded to the sound consistently even when they no longer wanted the reward.
Researchers said the transition appeared to occur suddenly, “as if a switch had been flipped.”
Brain Region May Control the Shift
Charlene Mohr, a lead researcher in the university’s Department of Psychological and Brain Sciences, said one of the study’s biggest surprises was that the animals changed strategies from one trial to the next without any change in the experimental conditions.
Additional recordings of brain activity identified a specific brain region that may be responsible for triggering the shift from deliberate actions to habitual behavior.
The researchers also found that some mice reverted to goal-directed behavior after extended periods of acting out of habit, suggesting that habits may be more flexible than previously assumed.
Kuchibhotla said many habits are beneficial because they free the brain to focus on other tasks. However, he added that if a control mechanism exists, it may eventually become possible to transform unhealthy habits into purposeful behaviors.
“Rather than viewing habits as permanent,” he said, “bad habits may not have to last forever.”
