“social smile.” In a social smile, a person consciously activates muscles at the corners of their mouth. Second, there is a genuine smile that happens spontaneously. In a genuine smile, the muscle that surrounds the eye — the orbicularis oculi — contracts. This muscle cannot be operated intentionally. Since contraction of the orbicularis oculi is strongly associated with delight, returning a spontaneous smile causes you to feel delight. A spontaneous smile is called a Duchenne smile, after the nineteenth-century French scientist Duchenne de Boulogne, who discovered the physiological and emotional differences between a social and a genuine smile.
When someone smiles at you, you reflexively return the type of smile you received. When someone flashes you their best social smile, the smile you reflexively return — lacking operation of the orbicularis oculi — produces no delight. If you have just gotten Botox injections for smile lines around your eyes and feel less pleasure when greeted by friends, now you know why. Botox can keep those delight-linked muscles from contracting. By contrast, when a friend is delighted to see you, muscles surrounding their eyes operate spontaneously. You reflexively return their spontaneous smile with a spontaneous smile of your own.
If you can think back to the feeling of delight you experienced when seeing and reflexively returning a genuine, spontaneous smile, you may begin to trust that unconscious processes involving the face can change what you feel in other ways. This chapter examines the neurological mechanisms that govern our responses to our world and make these changes possible.
The sympathetic nervous system, the system that increases arousal, does not require development. It works naturally. Every newborn baby is fully capable of getting revved up and screaming bloody murder (a state known as hyperarousal). But newborns cannot calm themselves by activating their own parasympathetic nervous system: it can be activated only by others. Babies are genetically programmed to be calmed by others who present an attuned face, a calm voice, and a loving touch.
As the child’s brain develops, it retains memories of the caregiver’s face, voice, and touch. If a caregiver responds consistently when the child is upset, the child comes to expect that the caregiver will appear to calm her. Anticipating this response, she imagines the caregiver’s face, voice, and touch. This imagination immediately activates the calming parasympathetic nervous system. The child is calm before the caregiver even reaches the child.
What happens next is important. If the child’s caregiver follows through with a calming response, the child’s expectations are reinforced, and a program begins to form in her unconscious procedural memory. The program has four steps. First, hyperarousal causes her to wish for her caregiver. Second, because her caregiver is dependable, she expects the caregiver to appear. Third, she imagines her caregiver’s face, voice, and touch. Fourth, imagination activates her calming parasympathetic nervous system. In other words, hyperarousal causes expectation, which causes imagination, which activates calming.
If these four steps are established as a program in the child’s unconscious procedural memory, hyperarousal will be automatically down-regulated to alertness throughout her life. She will not be subject to panic. Automatic down-regulation will allow her to think clearly under stress.
If, however, the caregiver does not respond as the child expects, there is no reinforcement, and automatic down-regulation is not established. Paradoxically, it is also possible that the program may not be established if the caregiver acts too quickly. The psychological theorist Heinz Kohut believed that “the most important aspect of the earliest mother-infant relationship is the principle of optimal frustration.” Automatic down-regulation develops when a child meets with some difficulty, acts to deal with the difficulty, and is successful. When things work too smoothly, there is no reason for a child to act. For example, if a caregiver calms a child before the child is frustrated enough to need the caregiver, summon her, imagine her response, and thus trigger the parasympathetic nervous system, no program to automatically down-regulate arousal will develop. On the other hand, if the child meets with too much frustration, the child learns that action is futile, and automatic down-regulation does not develop.
In any case, a child who does not develop automatic down-regulation is likely to fear hyperarousal. As an adult, they may need to be in control of every situation so that no hyperarousal takes place. They may need to avoid situations unless escape — a basic way to down-regulate hyperarousal — is available as a backup strategy if they lose control of the situation.
To understand how emotional regulation evolved, Stephen Porges suggests we look back two hundred million years, long before mammals arrived on the scene and even longer before humans made their entrance. At that time, the most highly evolved creatures were reptiles. The reptile’s amygdala monitored the environment for any kind of change, such as the presence of unfamiliar creatures. On encountering a new creature, the amygdala triggered the release of stress hormones that caused an urge to run away.
This was a useful response when the new creature was dangerous, because it protected the reptile from harm. But not every change or new creature was dangerous. Let’s imagine that an apatosaurus showed up. Being a vegetarian, the apatosaurus posed no threat to another reptile. Yet the amygdala still fired off stress hormones, and with no thinking part of the brain to deter this urge, the reptile followed the urge and ran away.
This primitive system, which Porges calls the mobilization system, produced a lot of false alarms. These were costly to the creature. Running away burns calories. In searching for food to replace those calories, Porges points out, the creature had to expose itself to additional dangers. Also, escape itself could result in injury — for example, the creature might fall over a cliff or be attacked by a more dangerous predator. The mobilization system’s protection was less than ideal.
As mammals evolved, they developed larger brains. Their capacity for thought provided more sophisticated protection. When a mammal’s amygdala released stress hormones, the hormones still produced an urge to run. But the stress hormones also activated the thinking and decision-making part of the mammal’s brain — the part we now refer to as executive function. The mammal’s executive function inhibited the urge to run and assessed the situation to determine whether escape was necessary. If it found that the change the amygdala was reacting to was not a threat, it signaled the amygdala to end the release of stress hormones.
Fast forward to humans. When you see a stranger, your amygdala-based mobilization system produces the urge to escape, just as it did in prehistoric reptiles. Simultaneously, the stress hormones activate your executive function, the high-level thinking that makes decisions. To give you time to look the stranger over, executive function overrides the urge to run. Tension develops as one part of the brain — the amygdala — tells you to run, and another part — executive function — tells you to hold on.
Meanwhile, something else is going on. You are exchanging unconscious signals with the stranger. If these signals indicate that the stranger is not a physical threat, your brain stimulates the vagus nerve to some degree. This slows your heart rate and overrides the effects of the stress hormones, causing you to relax. These signs that you are physically safe end the sense of alarm and set the stage for cooperation with this new friend (assuming that your brain interpreted the exchange of signals correctly).
This system, which Porges calls the social engagement system, allows two people to feel comfortable together. Down-regulating signals from our social engagement system helps us work together, live together, and mate. To understand how the social engagement system can override stress hormones, think of being in a car with an automatic transmission, with one foot planted solidly on the brake pedal. If the other foot presses on the accelerator and sends more gas into the engine, the brake keeps the car in place.
Porges refers to this overriding by the vagus nerve as vagal braking. Just as the brake pedal can slow your car down — even when gas is being pumped into the engine — the vagal brake can calm you down even when the amygdala is pumping stress hormones into you.
When you receive signals that the person you are with is not a physical threat, the vagus nerve causes you to feel physically safe. But when you receive signals that you are emotionally as well as physically safe, profound calming takes place. You feel your guard let down. This response is unconscious, a result of maximum