Why do we need sleep?

“My son will soon be ten years old and loves to sleep in our bed,” wrote a father recently to paediatrician Dr. Herbert Renz-Polster. “Do you think he will ever move on to his autonomous phase?”

“It will happen,” assured the doctor in his blog. “As children enter puberty, they become embarrassed by their parents.” Not only did Renz-Polster, the father of now four adult children, display his confidence in the matter, but also an unusual nonchalance in the face of one of the most emotionally charged issues of child rearing: sleep. At what age should children sleep in their own bed, alone in their room? When should they be able to sleep through the night and what methods should be used to ensure this happens? Is sleep, seemingly the most natural thing in the world, no or no longer a matter of instinct?

At night our brain continues to work at full speed

Humans cannot survive without sleep. We need rest at night to counterbalance the business of being awake during the day. Tension and relaxation, day and night, taking our life in our hands and then letting go – it all goes together. And yet, even as we lie asleep in bed, we are not really idle. Our brain, in particular, continues to work at full speed. In the dark, where we are not constantly bombarded with new sensory stimuli, when our energy is not expended on thinking, movement and digestion, the brain organises the impressions and experiences made during the day. It compartmentalises them, so to speak, so that we can start the new day with a clean slate. Furthermore, the organism as a whole undergoes regeneration. Sleep is not only the best medicine, but also the best prevention. People who don’t get enough sleep over the long term become more easily stressed, are more susceptible to infections and other illnesses and have a greater tendency to become overweight. In babies and young children, sleep fulfils another important developmental function: facilitating the growth of their brain, which triples in volume by the time they have reached 36 months of age.

For the father of the nine-year old son who still likes to slip into bed with his parents, Dr. Renz-Polster has other advice. In this case, it’s not only about the child’s autonomy, but also that of the parents. “If it no longer works for you, then speak with your son. Maybe he’ll enjoy thinking of a fun alternative, such as turning his own bed into a fort.”