As more generations are exposed to screens earlier and in more ways than ever before, one worry is that the constant sensory stimulation is competing with normally growing brain pathways for socialization and emotional intelligence.
Humans are inherently social. Infants instinctively read others long before they learn to speak. They can distinguish different facial expressions. But humans of all ages are vastly more interested in inferring the mental states behind the visible outer shell—another’s beliefs, desires, and intentions.
Early screen exposure competes with normal development because the first year of life is peak time for neural plasticity. For example, the visual cortex develops its forest of connections most rapidly during the first three months of life, and the postnatal brain grows in volume by one percent every day, tripling in size between ages 0–2.
Early experience is particularly important, and critical time windows exist during which a specific type of input (e.g., vision, hearing, touch) exerts its greatest effect on the developing brain. Patterns of synaptic connections establish themselves through repeated sensory simulation and motor actions.
Screens have made it difficult to be present—not just to others but to oneself. Dinner with a friend is marked by constant interruptions. Their constant presence shunts aside chances for spontaneous encounters, making it easier and more comfortable to relinquish attention to the screen than to make ourselves available to others.
One recent count has 18–to–24 year–olds checking their phones 210 times a day, or roughly once every five minutes. Rosen found that “heavy smartphone users showed increased anxiety after only 10 minutes” of not having access to their smartphone.