We carry out many of our activities mechanically without thinking about them, like walking, typing, eating, dressing, enunciating, and driving. Some activities become so automatic that if it would confuse us if we tried to think about them. For instance, We do not consider which foot we put forward first when we get up to walk. This is in spite of the fact that the Sunnah draws our attention to this act sometimes, by prescribing for us to enter the mosque with our right foot and leave it with the left.
Likewise, we do not normally think about where we place our hands when we go to sleep. Do we fold them on our chests or place them on the bed beside us?
Memorization requires making our recitation habitual. When we recite the Qur’an from memory, each verse follows naturally from the one before it. If we were to consciously think about which verse comes next, we would probably stop reciting or become uncertain and confused.
Human lives are built primarily of ingrained habits governing our feelings, thoughts, and behaviors. The same goes for society. Social customs are merely collective habits that everyone unthinkingly accepts. Because they are so ingrained, they are more powerful than laws. Our mode of dress is governed by such collective habits. They decide whether a man will will put on a shirt, pants, jacket and hat when he goes out in the morning, or a thobe, ghutra, iqal, and abaya.
There are societies without laws, like some nomadic tribes, but there are no societies without customs. In the same way every individual has habits.
Even animals who are mostly governed by instinct develop habits. Otherwise, they could not be trained. Allah says:
They ask you, [O Muhammad], what has been made lawful for them. Say, “Lawful for you are [all] good foods and [game caught by] what you have trained of hunting animals which you train as Allah has taught you. So eat of what they catch for you, and mention the name of Allah upon it, and fear Allah. Indeed, Allah is swift in account.” [Sūrah al-Mā’idah: 4]
Dogs are not only trained to hunt, they can be trained to sniff out drugs and detect explosive devices, even against their own instinctive nature.
Habits develop over time. We can grow accustomed to living in a hot or cold climate. We can get used to many kinds of hard work if we engage in it day after day, no matter how rigorous it might be. We can get used to the way our friends tease us. We can become experts in performing certain tasks requiring manual skill to the point of utmost proficiency, like we see when we watch craftspeople at work. The can carry out complex acts requiring great precision, and do so with speed and without error. In the same way, we become habituated in our ability to ride a bike, drive a car, or play a sport.
This is why so many habits develop around the necessities of life, like eating, drinking and sleeping. In the same way customs always surround the necessities of social interaction, like marriage, showing respect, and public dealings. Habits and customs fill in the details of our general activities.
A habit is like a well-worn path made by pedestrians through the woods. Once a path is established, you will not easily be coaxed into taking another route unless your attention is drawn to a path that is clearly much shorter or more comfortable.
Repetition brings about a physical, neurological affect in our brains. When you perform a task, it brings about electrochemical pathways in your brain, and each time you repeat it, the task gets easier and easier until it ultimately becomes automatic. This applies to good activities like kissing your father on the hand, as well as bad activities like smoking. So beware.
If habits did not exist, life would be impossible. It would take a full day to get dressed. Each time would be like the first. We would never be able to adapt ourselves to new circumstances. Habituation brings with it a set of skills. This is why it is easier for a person who plays football to learn to play basketball or volleyball than it is for someone who never played any sport before.