Children may look sweet, but in reality they are cute little barbarians, and it is our job to civilize them. Their brains are not tiny adult brains. They start out with little more than primitive reflexes (breathe, cry, wave my arms around when I’m startled), wander through childhood and adolescence (when they really can’t see the long term consequences of their actions), and don’t actually think like adults until, well, they’re adults.

At all these ages parents have to take into account their child’s personal style, intelligence, and talents when they make rules, but there are developmental stages that are universal, and understanding them will help a parent better resolve problems.

When babies are newborn, they can focus their vision well at about a foot away—just the distance of your face when you are holding them. They look at everything, learning at an unimaginable rate. By two months they recognize a smile and smile back. By four months, they will recognize your voice. Their thoughts aren’t well organized enough to allow them to become spoiled until about six months – so no, you can’t spoil them by holding them all the time. You also won’t do them vast harm if you need to put them down for a while.

At about nine months, they start to recognize words—“no” is generally one of the first. In baby language “no” means, “Smile at the parental units and keep doing what I’m doing. They will come play!” Saying it louder will only make them cry in confusion. Go over, distract them, and take away whatever they shouldn’t be playing with.

Curiosity rules for the first few years, and we want this. Babies look at and touch everything, often while putting everything in their mouths. They explore and, consequently, learn. Your job is to let them explore while keeping them safe. This is a lot easier to do by baby-proofing your house than by saying no every minute or two. Put all of the breakables out of reach, tuck away the electric cords, add padding to some of the more solid objects, and block off the stairs so you don’t have to follow Baby around all day. She’s not going to fully understand rules now anyway.

Between eighteen months and two years, most kids can begin to understand some rudimentary rules. Keep them simple, please—no complex commands. Saying, “You can’t play with that because Mommy needs it for work tomorrow” will elicit a blank stare. “No going near the road”  is more their size. Of course, they will do it anyway because they’re new at this whole rule thing—and because they finally have some control over their arms and legs, and there is neat stuff to play with. When Mommy or Daddy stops them, it’s terrible! The universe just ended! Tantrum Time!

Two year olds live at the center of their own universe; everything and everyone exists just for them. This can be seriously confusing for them when things don’t go their way. They really cannot understand why they can’t have and do what they want, because the world is theirs. They also have no idea how to regulate their emotions. We they are angry, they are consumed by that anger. Sadness is world destroying. Disciplining a two year old is aimed at teaching them to not hurt other people and to regulate their emotions. This is where the No biting and No kicking come in, along with the You can sit in your room alone until you can stop screaming.

Three and four year olds are still learning to modulate their emotions, but are also developing self-sufficiency… and opinions. Discipline at this age is mostly about consistency and endless repetition. They do know they can’t take that juice away from the table, but they think that maybe this time they will get away with it. At this age we want to reinforce the fact that bad behavior never gets you what you want. That juice is gone.

Enter the kindergartener. Have you ever noticed that most kindergarten teachers are young? They burn out quick. This is the age when kids start to learn about responsibility, and to feel guilt when they mess up. We make sure they understand the rules, remind them when they might bump into one, and enforce discipline immediately when they break one. At this age rewards work remarkably well, because kids are learning to feel pride when they do well.

The grade school years are your reward for making it through. Kids are very logical, not extremely emotional, and are focused more on learning and developing their skills and talents. They also at this age learn to deal with their failures, to discipline themselves  within their own internal framework of right and wrong. Where a kindergartener might hit another child and then feel bad, we want our third grader to feel like hitting another child but stop themselves.

Drum roll please… Adolescence. During these years teens break down and replace large portions of of their brains – the part would have given them a view of the future and the long term consequences of their actions, had it been there. They can be very impulsive and sometimes indulge in very risky behavior. Parenting in adolescence mainly consists of making sure they get enough sleep (a sleep deprived teen brain is a scary thing), keeping them alive, and protecting them from mistakes that will follow them forever. The most effective way to do this is to stay involved in their lives (even when they don’t want you to), know where they are and what they are doing, and keep communication open.  Discipline at this age is largely making sure they take responsibility for their actions because after adolescence you won’t be there to rescue them. Don’t save them from the small stuff (flunking grades) but make sure to protect them from the biggies (drugs, pregnancy, death).

The goal of discipline at any age is not to punish the child, but rather to  raise an inspired, responsible, self-reliant adult. Keep the long term in mind when you seem to be disciplining the exact same infraction over and over: you’re not aiming for a well behaved 2 year old or a teen who never screws up. You’re aiming for an amazing adult.

Want more specifics on how to make which rules? Check out 8 Surefire Strategies to Make Rules Work and 5 Reasons Why Kids Need Rules, and How Need Decides What Rules Should Be.