Our brains are first and foremost difference detectors. We distinguish known from unknown, familiar from unfamiliar, so that we can devote our energies to that which is new.

Were it not for our capacity to detect differences, every moment of every day would be overwhelming. In a world in which everything is new and equally deserving of attention, our senses would be swamped, resulting first in panic and then in total breakdown.

The structures that parents impose on children (and society imposes on us all) diminish anxiety by reducing novelty. Avoiding overload. Limits and consequences reduce the number of possible behaviors to those that will be rewarded and those that will be punished. Boundaries reduce physical space into “me” and “not me,” and in the process develop identity. Routines and rituals break the intangible, invisible expanse of time into a domino-like succession of predictable events.

A-then-B-then-C. Long before clocks, we relied on nature to make sense out of the passage of time. Cycles of light and dark defined days. Cycles of cold and hot defined seasons. The shifting appearance of the moon from new to full and back again defined months.

In the same way that children internalize the structures that parents provide, species internalize the structures that nature provide. Our bodies’ sleep-wake rhythm is synchronized to the planet’s day-night cycle. Our energy and neurotransmitters and hormones shift with the season.

Our children are acclimated to these rhythms long before they are born. Shifts in Mom’s heart rate and body temperature, activity level and two specific hormones—cortisol and melatonin—are so successfully communicated to the fetus throughout development that, by ten weeks before delivery, the two have synchronous REM sleep cycles.

Understanding how completely Mom’s body regulates her child’s experience gives the idea of holding tight and letting go a new depth of meaning. The miraculous and traumatic letting go that is birth is far more than the loss of immediate gratification. It means the loss of regulation as well. Gone are the signals that make sense out of time. The predictable drumbeat rhythm that always before set the pace and sequence of experience is suddenly absent.

Apart from the newborn, you still has one tear-filled, tired eye always on the brand-new baby — “I can’t believe I made him. He’s so beautiful!”—but he doesn’t know that. You’re completely confident that the separation will end. Experience has taught you the domino-like succession of time, so you can fight back the powerful urge to hold him. You can talk yourself through the anxiety. Hug your partner, talk to the doctor. Take your medicine. Nod politely like you’re actually listening. Calm and chaos without sequence or sense.

Held tight means order. Let go means chaos. Until the two become connected. Until the difference detector in his head recognizes this first, most primitive, and important sequence: Hold-tight leads to let-go leads to hold-tight. Separation leads to reunion. Anxiety can be tolerated. It will end.

This now leads to the next now. Experiences are strung together like beads on a necklace—like dominoes in line—making it suddenly possible to anticipate the next bead, one at a time. Chaos is a little more manageable if calm is next along the string of experience. Anxiety is a little less overwhelming if reassurance follows.

Letting go is tolerable if it reliably leads to holding tight. The baby’s capacity to expect or predict or anticipate—to infer next from last—may be only from one bead on the string to the bead that follows, but even that requires the idea of linearity. There is a string. ere can be order. This is a huge leap forward from living in random tumult and chaos. The idea that events occur in sequence opens the door to self- soothing. Once the child becomes able to expect calm and comfort, managing pain is a bit easier. Anxiety is reduced. Hormones settle. Blood that floods the body to enable fight or flight is redirected to the brain to enable more difference detection—learning.

Body rhythms once familiar in utero are re-established in those first joyful-painful-endless days after you bring the baby home. New parents eat and sleep and bathe helter-skelter around the baby’s needs. We pick him up and put him down, clean him and diaper him, feed him and rock him almost at random, trying to learn his signals as he tries to learn ours. Our difference detectors are running full tilt, trying to make sense out of experience. This is the most immersive language learning lesson anyone will ever endure, but the language learned has no words. It’s a language of sequence or order, more like music than lexicon, because it relies on rhythm.

In those first days and weeks after birth, parent and child (re-)establish mutual rhythm. An A-then-B-then-C pattern of need and comfort, need and comfort. This is likely as poor a substitute for the rhythm that spontaneously and unconsciously arose in utero as it is a poor approximation of the rhythms of the adult world, but it works for a while. It likely begins with many cycles of food and rest and elimination as mother and child (re-)build their strength. Gradually, the rhythm slows. The cycle lengthens. the pattern between parent and child more or less synchronizes with the pattern between parent-child and family, and then between family and community, community and nature.

A-then-B-then-C becomes more than a cycle of wakefulness and comfort; it becomes a way of thinking-feeling. It’s not that the baby hears the front door open and says to himself, “Mom’s home. Food’s coming.” It’s the sensory-emotional association between cause and effect. Door sound anticipates comfort.

Let-go anticipates hold-tight. Scream and ail anticipates pick-up. Pick-up anticipates calm. Supper anticipates warm, soothing bath, which anticipates sleep. Alarm clock anticipates breakfast, which anticipates school bus, which anticipates friends.

Work anticipates paycheck, which anticipates buying, which anticipates pleasure (or, in the case of bills, pain relief). When the world is in chaos, there is no room left for novelty, learning, and growth. Exploration shuts down. We retreat into the familiar. But when the world is ordered and predictable, anxiety is diminished. The difference detector can devote greater resources to novelty and growth. is reality often prompts me to recommend to parents that their goal should be to be boring.

Boring means predictable. It means that the world is familiar and safe. If little or no emotional energy needs to be devoted to coping with home, then most or all of that energy can be directed outward. Go ahead and have fun. Laugh and play and dance, but make sure that events like bedtime and mealtime and bath time and homework—who is there and when—are all familiar. That life at home is A-then-B-then-C.