Let me tell you about a patient I know, Ms. X. She is in her mid forties, a bit overweight and somewhat disheveled. She has four children with three different fathers, only one of whom she had married and then divorced. She has average intelligence, but is socially awkward. Maybe awkward is not the word. Forward is better, or inappropriately intimate. She commonly reveals lots of personal information that most of us would be embarrassed to tell our best friends, therapists, or priests. She doesn't seem to sense the expressions of disgust people have when she describes her sexual life or recent medical exam.
When tested, Ms. X is impulsive, socially fearless, and terrible at "reading" people. More to the point, she does not change her behavior as she interacts with different people: friends and strangers, old and young, kindly or malicious, all are treated as intimates. Unfortunately, this means that Ms. X is often a target for predation. She has lost significant amounts of money to those she trusted that she should not have.
Ms. X has a rare genetic disorder that has damaged a single structure in her brain. If you were to meet her, she would appear at first as "normal" as any one of us. Yet, she cannot do what most of do quickly and effortlessly: assess the moral character of those we meet.
Think about it: nearly every day you interact with a sea of strangers. Most of them have intentions that are neutral or considerate toward you. Some small subset of people cannot be trusted, and we watch these people carefully to maintain our safety. Indeed, we spend considerable energy teaching our children to beware of strangers. We have to do this because while actual violence due to strangers is rare, when it occurs it can be catastrophic.
The teaching of children is meant to tune their oxytocin systems. Because most children begin their lives with loving attachments to adult caregivers, the oxytocin system rapidly develops to facilitate reciprocal love: you are nice to me and I'll be nice to you. Most children have some stranger anxiety, but adults work to appropriately tune this system. Uncle George or neighbor Sue or teacher Ann should, we intone, be treated like family; others you need to avoid. All parents know that we also use the fear response to get children to behave, from raised voices to time-outs to spankings; these tell children that adults can be scary as well as loving.
Ms. X does is missing the fear-processing regions of her brain. When she encounters new people, she is unable to adjust the love-fear, approach-withdraw spectrum that oxytocin modulates. Everyone is family to Ms. X. Patients with a spontaneous genetic disorder called Williams Syndrome also treat everyone as family.
Williams Syndrome occurs in 1 out of every 20,000 live births in the US. These patients are missing a suite of genes on chromosome 7, including one that codes for a gene called elastin. Elastin does what it sounds like, keeping tissues elastic. Williams Syndrome patients typically have drawn or "elfin" facial features, heart defects, and moderate mental retardation. They are also hyper-acute to sounds, typically love soft music, and are unconditionally trusting. Others with congenital disorders like autism or Down Syndrome do not typically trust everyone, but Williams Syndrome patients do for reasons not yet fully understood.
It is likely that oxtytocin is running in high gear in Williams Syndrome patients: they are hyper-responsive to the smallest opportunity for social interaction. They seek it out, invade your physical space, and invade your emotional space. They are super-trusters. Like Ms. X, this is clearly maladaptive because predators are out there. Predators do serve a valuable function-they keep us on our neural toes. That is, they allow us to tune oxytocin so that we are watchful and careful when the situation calls for this, and cooperative and reciprocal otherwise.
Both Ms. X and Williams Syndrome patients reveal how powerful oxytocin can be when it is unregulated by cognitive brain regions. Fear is the flip-side of trust, and balancing these is essential for the social species Homo sapiens.
