Like HowStuffWorks on Facebook!

Do old habits really die hard?

Changing certain habits could be a matter of life or death, Are you ready to take the plunge and figure out what your root is?
Changing certain habits could be a matter of life or death, Are you ready to take the plunge and figure out what your root is?

When you're trying to break a bad habit, even the word "habit" can develop a nasty connotation, but this isn't necessarily the case. Imagine what your life would be like without any habits at all; the very process of getting out of bed and getting ready for work each morning would leave you utterly exhausted and overwhelmed before you even stepped out the door. Habits allow us to perform mundane tasks without thinking about them, leaving the brain free to focus on more important matters instead of figuring out how to work a toothbrush every morning.

Yet, as beneficial as habits can be most of the time, breaking a bad habit can truly change your life for the better. Once a habit has become ingrained, however, it may seem impossible to break. This difficulty in breaking a habit can be traced to neural pathways in the brain, which can be tough to remove or alter once they've been established.

In a 2005 study, scientists tested rats to see how their brains handled the making and breaking of habits. The rats learned to travel down a specific path to reach a reward – chocolate...the universal reward – and eventually, these paths grew into habits, allowing the rats to travel them without thinking. When scientists removed the reward, the rats ditched the habit and the path disappeared. Once the chocolate was reintroduced, however, it was clear that the pathways in the brain related to this habit never really went away. The rats immediately picked back up their old habit of running a set path to reach the reward [source: Delude].

What does this mean for you? It suggests that even if you are able to drop a habit, the path in your brain required to perform this habit remains. That means it only takes one small catalyst to fire the habit back up and make it a regular part of your life once again.

Even replacing a bad habit with a better one – going for a run when you really want a snack, for instance – doesn't eliminate the path in your brain that tells you to grab that cookie. Fortunately, if you continue to reinforce your new good habit by running instead of snacking, you'll be able to strengthen the running habit pathways while suppressing the ones related to excess food consumption [source: Contie].

But if you're really committed and you have enough willpower, everyone knows that breaking a bad habit or creating a good one takes just 21 days, right? While no one knows where the 21-day myth originated, it may have stemmed from a 1960s book on self-image and plastic surgery which had nothing to do with habits [source: Gardner].

Far from taking 21 days, habits take an average of 66 days to establish, according to a 2010 study. If you find yourself slipping, take heart – some participants in this study established a new habit in 18 days, while others took an estimated 254 days [source: Lally and Gardner]. The lesson? While old habits die hard, persistence pays off when it comes to making changes.