Psychiatric Annals

CME Article 

Scientific Foundations for the Social Brain Concept

Beverly J. Sutton, MD

Abstract

Psychiatry and its social brain foundation depend on scientific study, but areas requiring emphasis vary over time. A new overview of the social brain fosters a different arrangement of relevant data. This article presents a summary of relevant research arranged in a novel manner: it reflects the integrative values of the social brain concept, retaining the biomedical base while also emphasizing affective, moral, and cultural developments of interacting people. Selected examples of developmental studies are used, concluding with treatment implications.

Animals, including humans, seem innately ready to learn certain behavior. This readiness, called “prepared learning,” possesses adaptive advantage and illustrates Darwinian fitness (ie, passing genetic advantages to offspring). The human genome uses tens of thousands of protein-encoding genes. More sequence tags (messenger RNA) exist in the brain than any other organ, apparently to foster brain function. Just as some body features possess ancient roots (eg, having a similar body plan, with four limbs), some behavioral patterns have ancient origins, such as social rank hierarchy and territoriality. A new research field called “evo devo” (evolution and development) explores emerging conceptions about consistencies in molecular building blocks of animal structure and development that have persisted over evolutionary time, as well as delineating differences that have resulted in the many species and the individual differences within species. Such similarities and contrasts include sociality.1

The vertebrate cranial vault of today, including the human, resembles that of vertebrates 480 million years ago.2 In the past 3 million years of developmental trial and error in the evolutionary process, brain volume increased about fourfold. The neocortex comprised much of this growth, expanding areas of “language and its symbol-based product, culture,” although old systems influence the developments.3 Having a large brain in humans, however, does not always indicate increased function — for example, autistic people often are retarded intellectually and are asocial but may have large brains.4 Recently discovered fossils of island-dwelling humans showed brain complexity even with small brain sizes. Allman found that social group size accounts for 45% of brain-size variance.5

Human brain studies further show that localized areas process emotional content and social cognition, including the amygdala, prefrontal cortex, and the right somatosensory cortices.6 Positron emission tomography studies show medial prefrontal areas and the thalamus activate during normal emotion. Sensory association areas and the anterior temporal lobe likely provide emotional color to sensory information. Anterior insular regions invest cognitive and sensory information with negative emotional meaning.7

Historically, philosophers thought moral judgment relied on pure reason, but current study shows that ethical dilemmas activate emotional areas of the brain such as the medial frontal gyrus, posterior cingulate gyrus, and angular gyrus.8 Sexes differ in moral matters; a woman's standards tend to involve responsiveness to others, whereas men's morality ties to rules of fairness and separateness. In both sexes, emotions generated by moral decisions activate the neurotransmitters dopamine and serotonin, which relate to positive and negative feelings. Dopamine, a “pleasure chemical,” releases after eating, pleasant sexual interaction, or taking cocaine. Decreased serotonin connects to the negative feelings of depression, suicide, anxiety, and social phobia, whereas serotonin reuptake inhibitors increase optimism and social confidence.9

Evolution actually may preserve certain types of psychopathology. Eliminating some vulnerabilities may also limit behaviors and mental states necessary for survival/reproductive success.2 No study shows genetic variation accounts for all behavioral variations between mentally ill and mentally healthy people.10 Even so, chromosomal disorders result in behavioral and social problems including Fragile X, Prader-Willi, and Angelman syndromes. The latter two involve chromosome 15 and genomic imprinting. while women transmit the full mutation for Fragile X to their sons, who show retardation, delayed language development, attention…

Psychiatry and its social brain foundation depend on scientific study, but areas requiring emphasis vary over time. A new overview of the social brain fosters a different arrangement of relevant data. This article presents a summary of relevant research arranged in a novel manner: it reflects the integrative values of the social brain concept, retaining the biomedical base while also emphasizing affective, moral, and cultural developments of interacting people. Selected examples of developmental studies are used, concluding with treatment implications.

Brains, Genetics, and Behavior Through Development

Animals, including humans, seem innately ready to learn certain behavior. This readiness, called “prepared learning,” possesses adaptive advantage and illustrates Darwinian fitness (ie, passing genetic advantages to offspring). The human genome uses tens of thousands of protein-encoding genes. More sequence tags (messenger RNA) exist in the brain than any other organ, apparently to foster brain function. Just as some body features possess ancient roots (eg, having a similar body plan, with four limbs), some behavioral patterns have ancient origins, such as social rank hierarchy and territoriality. A new research field called “evo devo” (evolution and development) explores emerging conceptions about consistencies in molecular building blocks of animal structure and development that have persisted over evolutionary time, as well as delineating differences that have resulted in the many species and the individual differences within species. Such similarities and contrasts include sociality.1

The vertebrate cranial vault of today, including the human, resembles that of vertebrates 480 million years ago.2 In the past 3 million years of developmental trial and error in the evolutionary process, brain volume increased about fourfold. The neocortex comprised much of this growth, expanding areas of “language and its symbol-based product, culture,” although old systems influence the developments.3 Having a large brain in humans, however, does not always indicate increased function — for example, autistic people often are retarded intellectually and are asocial but may have large brains.4 Recently discovered fossils of island-dwelling humans showed brain complexity even with small brain sizes. Allman found that social group size accounts for 45% of brain-size variance.5

Human brain studies further show that localized areas process emotional content and social cognition, including the amygdala, prefrontal cortex, and the right somatosensory cortices.6 Positron emission tomography studies show medial prefrontal areas and the thalamus activate during normal emotion. Sensory association areas and the anterior temporal lobe likely provide emotional color to sensory information. Anterior insular regions invest cognitive and sensory information with negative emotional meaning.7

Historically, philosophers thought moral judgment relied on pure reason, but current study shows that ethical dilemmas activate emotional areas of the brain such as the medial frontal gyrus, posterior cingulate gyrus, and angular gyrus.8 Sexes differ in moral matters; a woman's standards tend to involve responsiveness to others, whereas men's morality ties to rules of fairness and separateness. In both sexes, emotions generated by moral decisions activate the neurotransmitters dopamine and serotonin, which relate to positive and negative feelings. Dopamine, a “pleasure chemical,” releases after eating, pleasant sexual interaction, or taking cocaine. Decreased serotonin connects to the negative feelings of depression, suicide, anxiety, and social phobia, whereas serotonin reuptake inhibitors increase optimism and social confidence.9

Evolution actually may preserve certain types of psychopathology. Eliminating some vulnerabilities may also limit behaviors and mental states necessary for survival/reproductive success.2 No study shows genetic variation accounts for all behavioral variations between mentally ill and mentally healthy people.10 Even so, chromosomal disorders result in behavioral and social problems including Fragile X, Prader-Willi, and Angelman syndromes. The latter two involve chromosome 15 and genomic imprinting. while women transmit the full mutation for Fragile X to their sons, who show retardation, delayed language development, attention disorders, and pervasive developmental disorder symptoms. Many carrier daughters show problems with social relationships, as they are shy with poor eye contact; 25% of carriers have an IQ below 70.11 Fragile X syndrome stems from a mutation of the FMR locus at Xq28; a molecular component repeats, the extent of repetition correlating with severity of the clinical presentation.

In genomic imprinting, the same gene expresses different characteristics, depending on whether the mother or the father furnished the DNA. Part of the imprinting process involves DNA methylation, which switches off gene expression. Prader-Willi syndrome shows in infancy with a typical hypotonia and failure to thrive. Paternally derived, the genes at 15q11-13 impair function of hypothalamic and septal structures but not the cortex. These short patients demonstrate emotional lability and intellectual slowness; notably, they overeat to the point of extreme obesity unless restrained.

By contrast, genes of the same area transmitted to the child by the mother produce Angelman syndrome. Here, the pathology resides in the neocortex, causing a more serious clinical problem both socially and cognitively, with severe retardation, posturing tendencies, and frequent laughter. Spasmodic laughing or crying usually points to corticobulbar tract pathology.3

Williams syndrome exemplifies a genetic metabolic disorder from a microdeletion on chromosome 7 with a clinical picture of mild mental retardation, cardiac and connective tissue problems, profound visuospatial dysfunction, and characteristic facial features; a normal-sized frontal cortex contrasts with small posterior lobes.12 The disorder uniquely features excessive sociability with fluent language. Forty percent of people with Moebius syndrome, an autosomal dominant condition, exhibit autism and bilateral Cranial VI and VII paralyses; these combined with lateral gaze problems produce a characteristic expressionless face.2

Social Behavior in Nonhuman Animals

Environmental events induce quantitative changes in neurophysiology. The first study linking a social behavior to a change in a specific synapse showed that a large neuron in crayfish responded to serotonin differently depending on the social status of the animal.22 It produces the tail-flip response used for fight or escape. Serotonin added to it enhanced neuron firing rate in dominant animals but suppressed firing in subordinates. If two subordinate crayfish are put together, one must win, resulting in a new dominant, in which serotonin shows increased excitability in the same neuron. However, injecting serotonin into lobsters and crayfish produces aggressive dominant behavior only.

Decreased serotonin activity has been linked to depression, anxiety, and hostility.23 In laboratory rhesus monkeys, a birth-order effect caused later-born baby monkeys to produce lower cortisol levels, indicating lower levels of stress, perhaps reflecting improved care from more experienced mothers.24 A study of white-crowned sparrows revealed hormonal changes secondary to increasing day length controlled development brain areas used for singing.25 The bird's social behavior also held importance; males with females had 15% to 20% larger brain song areas than bachelors or males living in all-male groups.

Overcrowding can alter nonhuman social behavior. Overpopulation in an area with insufficient food induces the worm Caenorhabditis elegans to enter a dauer, or suspended animation phase, for 2 or more months (the worm's equivalent of 300 human years). A daf-2 gene inducing the dauer period produces a protein that acts like an insulin receptor. Environmental extremes may have selected for the daf genes; a similar type of arrest seen in many vertebrate and invertebrate groups seems to prolong the reproductive period. Indeed, the increasing prevalance of obesity and type II diabetes in humans may reflect survival of past generations from famine.26 Similarly, functional hypoglycemia may have helped human adaptation to infrequent but large food supplies.

Wild Norwegian rats raised in a confined space eventually stabilized their numbers.27 With increased numbers, mother rats' caretaking behavior deteriorated, likely from disordered social rank effects. Fewer young survived, so the number living in the confined space stabilized. Rats raised in isolation show behavior changes and high levels of dopamine. Dopamine is important in addiction, motor control, and perhaps schizophrenia. Dopamine-blocking agents ameliorate symptoms in these rats.

Maternally deprived rats show low levels of serotonin.24 Rat pups handled by people may show less fear because of their mother's behavior when the pups return to the nest; the rat mother does extra licking, grooming, and nursing. Baby rats with such “mindful” mothers develop more neurotransmitter receptors that decrease amygdala activity and fewer receptors for corticotropin releasing hormone involved with stress. Amygdala stimulation produces rage in some animals.28 Amygdalar lesions produce docility. Field studies of chimpanzees show variation in patterns of tool use behavior, grooming, and sexual behaviors. Different chimpanzee groups exhibit unique styles of communal behavior previously thought characteristic of human cultures only.29 In humans, lower social status correlates with lower serotonin responsivity.30

Dominance status in animal groupings typically correlates with reproductive success and control of resources. However, dominance studied with reproduction DNA studies showed second- or third-rank rhesus males may impregnate females opportunistically while the dominant male worked to maintain territory.31 Among great apes, females vary little in reproductive behavior, passively receiving male sexual advances. By contrast, baboons and macaques show levels of breeding success that parallel standing in the female hierarchy. In Gombe chimpanzee studies, infant production, infant survival, and infant development indexed female fitness; dominant chimpanzee females weaned twice as many infants than nondominants.32

Parent–Child and Child–Child Interactions

Interaction between human parents and their children, as well as between sibling children, can have profound developmental effects. Children who receive more maternal affection than their siblings express less depression or other internalizing symptoms at later life points.15 If parents display physical conflict, children show more problems than parallel exposure to verbal conflict. Boys express more behavior problems when exposed to parental disagreement about child rearing. When parents constructively disagree, the children play, smile, and laugh as if nothing important has happened.

A study of mother–child interactions illustrated the sensitivity of development to interpersonal factors, including ideas about one's children.13 Movie-frame microanalysis of mother–child gazing used the code of “attracting” contact if the two made visual contact but “avoidance” if either the mother or infant looked away from the other for a fraction of a second. This behavior could not be seen on direct observation. The mother and the twin she identified with her husband used avoidant head movements with each other that contrasted with an attracting pattern with the other twin, with whom the mother identified. A year later, when 12 to 15 months old, the avoidant twin acted more fearfully and with more dependency compared with his more independent brother, who had better social skills.

When mothers maltreat their infants, 82% of the children show disorganized behavior at age 12 months, compared with 19% of controls. At age 36 months, 35% of maltreated infants remained disorganized and 21% securely reactive compared with control infants, with the opposite rates of 27% disorganized and 71% secure. Maltreated infants withdraw physically and emotionally, using fewer internal state words than nonmaltreated infants with otherwise similar vocabularies.15 Abusive behavior persists; abused children likely become abusing adults, maltreating their children in the next generation, as well as elderly parents.

Adolescent mothers (younger than 16) talk to their children less but command more. They smile less and touch base less with eye and physical contact compared with older mothers; the children exhibit poorer cognitive and language outcomes.15 Young mothers display less sensitivity to their children but more intrusiveness. The children show more avoidance; punitive discipline results in more aggression, impulsivity, social withdrawal and fewer friends. These mothers underestimate their children's ability to think, interact and communicate but overestimate mastery of the next developmental level.

Parental expectations regarding their unborn baby strongly predict the infant's attachment behavior beyond the first year.14 Developmental capacities change at age 2 to 3 months so the infant becomes less fussy, which permits the mother to decrease her caregiving while increasing social interchange, but if fussiness fails to decrease, maternal attachment decreases. By age 7 to 9 months, infants behave as though they know that others can understand their thoughts, feelings, and behavior, and they show preferences for a few caregiving adults.15 A toddler requires a sense of self to experience pride and shame.6

Visual experience at key ages produces important changes during critical periods. Infants with congenital cataracts from birth to age 2 to 6 months show permanent problems in discriminating facial configurations that vary, for example, by spacing between features. Although normal infants possess limited visual acuity, early exposure to faces sets up neural circuits that enable facial processing in the first 10 to 12 years of life. Children who undergo cataract surgery after an early sightless period identify geometric patterns as well as children with normal early vision, but they don't recognize minor variations in facial configuration as readily (in adults, different neural systems process faces and geometric objects).16

Postnatally, infants show ability to discriminate sound — they prefer the mother's voice over those of other women.17 French infants, 4 days old, suck harder when they hear a recording in French than Russian; perhaps they acquired this preference in utero.18 Month-old infants viewed negatively by their mothers exhibit a sixfold greater likelihood of psychosocial developmental disorder at age 19 compared with positively viewed controls.14

A family's sibling sequence also produces systematic influences that mold attitudes and behavior.19 Firstborn children tend to identify with power and authority, whereas later-born children question the status quo and resist pressure to conform. Firstborns are more likely to become political leaders and establishment scientists, whereas socially successful later-borns support unpopular causes. Six or more years between siblings restarts the birth order effect (ie, another firstborn child seems to appear). Siblings also perceive differences in the way they are treated; this continues throughout the lifespan. Children who felt that one or both parents provided more affection reached higher academic and occupational goals.10

Parent–child and child–child conflicts differ.19 Sibling struggle to gain maximum parental resources is a conflict not sex linked, not associated with a parent of the same or opposite sex, nor the result of sexual drive. Each child wishes for greatest benefit from both parents. If a favorite child exists in a family, “make sure that you are the favored one.” This generates sibling rivalries, but the competition generally proves adaptive, as does altruism among siblings.

Parents using mild, inductive techniques of behavior management produce children with high moral development. Benign management, in the form of ignoring negative and rewarding positive behavior, better socializes poor inner-city children (of any race) than do conventional restriction and punishment-oriented classes. The effect holds from kindergarten through eighth grade. Attractive children usually gain more popularity; peers favor tall, thin ectomorphs, rather than short, fat endomorphs.20

Culture

Human beings started evolving about 7 million years ago from ancestral forms in Africa. Homo sapiens appeared about 500,000 years ago and used crude stone tools and fire. By 40,000 years ago, Cro-Magnons (modern man) left evidence of stone and bone tools, nets, jewelry, clothes, spears, bows, and arrows. They also painted, sculpted, and played musical instruments. Ships appearing 13,000 years ago made it possible for people to travel outside land-masses.33 The agricultural revolution commenced about 10,000 years ago in the Middle East, China, and Mesoamerica. This allowed more people to live in discrete areas without needing to move for food. After their domestication in about 4,000 BC, horses enhanced travel and farming. Food supplies obtained by farming caused rapid population increases. Average time between children was 2 years for farm people but 4 years for hunter-gatherers.34

Over time, cultural norms have been produced by the group mind, but each individual mind possesses genetic determinants. Gene-culture co-evolution represents a special form of natural selection.3 The concept of the social brain provides a focus for study of this special form of co-evolution, as culture provides a special environment for behavioral genes. The definition of culture hinges on everyday ways of doing things, preferred forms of interaction, and what people feel to be “common sense.”28 Culture also determines what people consider normal, including how illnesses have meaning and the necessary elements for cures. Bodily expression of a mental illness represents an attribution more common than psychological. Thus, the criteria used for psychiatric diagnosis in the United States concentrate on psychological presentations that may be unsuitable for diagnoses in non-Western areas. People on this continent from non-Western cultures often receive misdiagnosis and incorrect treatment.

Some psychological areas do cross cultural boundaries. People in all cultures detect accurately the facial expressions of fear, anger, disgust, sadness, surprise, and happiness. Infants less than 71 hours old mimic facial expressions.34 Infants 1 to 9 months old express distinct, situationally appropriate facial emotion. Some of these seem innate, not learned or imitated. Awareness of emotional communication helps youngsters respond appropriately to social experiences; 89% of 4- to 5-year-olds rely on facial expression to determine another's emotional state. By ages 8 to 9, children may use facial and situational cues to assess emotion.6

Bilateral amygdalar damage impairs the patient's ability to recognize facial expression of fear. Measurements of manic, euthymic bipolar, and healthy persons' ability to identify facial expression showed that euthymic bipolar and healthy persons scored similarly, but manic patients had deficits in recognizing negative emotions, particularly fear and disgust.35 They frequently evaluated a fear face as expressing surprise.

Differences also may be seen between smaller groups and larger groups. Small groups tend to place importance on physical grooming behaviors, while social interaction in larger groups emphasizes the use of social “grooming,” such as talking and rituals. Cultural, including religious, rituals reduce anxiety, make sense of experience, and provide hope.36 Compelling and powerful experiences of this kind enhance social control. Further, the group ritualistically sets the ways that people behave when eating, grooming, and otherwise interacting with one another. Religious ceremonies and courting behavior may entail inflexible components of behavior required by all. As a part of social rituals, group members understand the acceptability of only certain ways to behave, with role-playing helping to learn these. In obsessive-compulsive disorder, actions and thoughts echo social ritualistic behavior but often differ from accepted social conventions in extent and timing.37

Culture may play a role in genetic diversity. Seventy percent of human societies expect a bride to move to her husband's birthplace (patrilocal). Study of three matrilocal (men move to woman's birthplace) and three patrilocal groups in northern Thailand showed findings expected from the chromosome characteristics of the different sexes: patrilocal groups exhibit high variation in mitochondrial DNA (mtDNA) inherited only from mothers but low variability in the y-chromosome (transmitted to sons from fathers).38 Matrilocal groups showed low mtDNA and high y-chromosome variability.

Adult social roles reflect long exposure to family and cultural dictates.21 Even with a stable marriage, women maintain networks with other women. Although intimacy tends to threaten men, divorced men remarry faster and more often than divorced women. Men exhibit less depression than women, less often seek help, and respond faster to treatment. Women, on the other hand, show more panic disorder and somatization disorders. Men exhibit more alcohol dependence, antisocial personality disorder, delusions about homosexuality, paranoid disorders, and compulsive disorders. Most men value working and earning money; men in “pink collar” jobs (jobs typically held by women) face derision by uninformed or homophobic community members.

In the United States, about 10% of families meet a “traditional” expectation of man-provider and woman-homemaker. Dual-career marriages, single-parent families, lesbian and gay parents, complex or “blended” families (children from former marriages), boomerang families (adult children returning home), and adult-oriented multigenerational families produce unique child care practices.21 Male elders provide important superego models and cultural supports to the family as a group.21 White women more likely work for economic independence compared with black women, who work from economic need.21 Between one-third and two-thirds of women in the US experience abuse from their spouses each year. Although the economics of divorce usually increase a man's and decrease a woman's standard of living, men show more psychological and physical distress than women from separation and divorce.

Cultural Perspectives on Psychiatric ‘Symptoms’

The human ability to attribute mental states to others allows awareness of another person's thoughts and feelings.6 How a person experiences depression varies with culture; for example, American Indians, Alaskan Natives, and Southeast Asians possess no word for “depressed.” Eskimos and Tahitians rarely show anger. Iranians encourage but Navajos discourage displays of extreme sadness. Javanese seek serenity. Hopi commonly express sadness, so that 1 month of this symptom should elapse rather than the usual 2 weeks for the symptom to acquire significance in diagnosing depression. A woman staying at home at all times might be agoraphobic in the West but virtuous if Muslim.

Culture-bound disorders exist in all countries, and their reasons stem from anger, fright, witchcraft, “evil eye,” preoccupation with bodily function, or other precipitants.28 Anxiety disorders reflect bodily arousal, cognitive interpretation, and ineffective coping skills, all influenced by cultural belief and practice. Blood-injury phobia represents the only anxiety disorder characterized by not a rise but a drop in blood pressure.

In the West, Caucasians particularly struggle for thinness, while in some countries, only overweight people gain attractive status. In England, people feel great concern with constipation and chilblains, so that physicians may ignore these complaints. In contrast, French people typically complain of fatigue and headache, plus other problems, caused by “liver crisis.” German physicians vigorously treat low blood pressure or poor circulation. In one study, 16% of people interviewed in Puerto Rico had a history of “ataque de nervios,” somatic and dissociative symptoms after a stressful event.28

People usually learn drug use from peers. Heavy alcohol use characterizes some groups in northern and western Europe; if an American Indian refuses alcohol, peers may consider the abstinence impolite. Buddhist monks do not drink alcohol, nor do Muslims. Use or nonuse of alcohol during the observance of a cultural ritual varies with group and country. Some groups of American Indian and Hispanic American men engage in all-day drinking parties.28 At funerals, Irish Americans drink and tell jokes; African Americans grieve and sing spirituals. Lack of an enzyme, alcohol dehydrogenase, makes some Asians flush and feel sick with alcohol.

Some religious ceremonies regularly involve the use of mind-altering substances. Drugs seem to take over the reward systems in the brain. Knockout mice that lack a dopamine transporter protein show “no interest” in cocaine or amphetamine.39

Environment and culture change violent expression. Exposure to it usually increases aggression.28 Drug addicts may use violence to obtain drugs. Willingness to use violence to maintain the status quo typifies firstborn, conservative, tough-minded behavior.19 Aggression typifies boys' behavior on the playground unless supervised at “play” by adults who stop predatory behavior, model nonviolent behavior, and teach social skills. In one study, teaching non-violence in an elementary school resulted in increased academic performance and a decrease in disciplinary referrals.40 The program emphasized zero tolerance for pathological behavioral roles (bully, observer, victim) while teaching appropriate social behaviors.

Language

Culture construction depends on language designed to provide information. Language shapes thinking and new words provide ability to think in new patterns. Words can change the way we feel and serve as substitutes for other behavior. Language unites those in a social group; members of a group hold it in high regard. In some areas, such as Belgium, French-speaking Canada, and Basque-speaking Spain, religious and political turmoil resulted from use or nonuse of a preferred language. In Genesis Chapter 11, Moses protested that he could not lead the people of Israel because he had difficulties with language.

Until recently, communicating with language seemed specific for humans. However, chimpanzees can communicate with sign language and also teach their babies to use it. A pygmy chimpanzee learned to respond to oral English language to an extent comparable to a 2-year-old human infant.6

In humans, evolution of the larynx to a lower neck position made it possible to create more sounds.41 The brain reorganized to accommodate this function particularly in the frontal area, including Broca's area. Human speech uses 50 sounds, or four times the number used by other higher primates; people can discriminate about ten sounds per second, in the range needed to decode speech. About 5,000 languages presently exist, with associated distinctive cultures.

Unique language uses have evolved. “Baby talk” exemplifies intuitive parenting; this high pitched, slow, and melodious verbalization attracts the baby's attention and encourages attunement. A cultural group that shouts at one another uses easily recognized vowels, that is, the loudness of verbalizations is inversely proportional to the number of vowels in their language.42 Dunbar noted that about two-thirds of human speech is gossip.42

Stress on a sound or change in rhythm of the sounds may change meaning (eg, in Chinese) or emotional tone (eg, in English). In some countries, such as Japan and Korea, words chosen must fit the relative social status of the participants. Over half of Japanese sentences omit the subject, reflecting the favored indirect approach. Japanese and American Indian languages contain no native swear words. An extremely crude swear word may arouse anger in one culture but no emotional reaction in another culture.

Reciprocity with the mother provides an organizing principle in a developing child for all forms of communication. Sentences leave “mind traces” that make thoughts easier to follow. Social referencing at age 6 months seems designed to seek reassurance from a parent's presence, but by age 1, the infant also seeks information from the parent's face. Young children may interrupt play to reference the mother for emotional information.6 They also then express feelings in words and talk to themselves to change both their own feeling states and perceptions of an environmental situation.

Infants make a great variety of sounds until about age 10 months, the number then decreasing, a change that stems from the restricted set that the baby hears in the family language.6 At age 1 month, the infant can distinguish a “ba” sound from a “pa” sound. A 1-year old has two to three words, and about 20 signs when exposed to sign language. At age 2, the child knows 50 words. Factors forecasting large vocabularies include adults reading and talking about stories, quality of mealtime conversations, large vocabulary and mean length of utterance by the mother, higher socioeconomic status of family, firstborn status, and a talkative mother with sophisticated language.43

Sexes equate on overall intelligence, but men excel on visuospatial abilities (especially mental rotation of complex figures) and women on verbal abilities (especially fluent production of words).21 Girls with developmental language disorders withdraw more, and boys with the disorder tend toward hyperactivity.42 Children with speech and language disorders followed for 14 years showed higher rates of anxiety disorder (social phobia) than controls.43 Men who had been language impaired display more antisocial disorder compared with controls. Children who are language impaired tend to exhibit other psychiatric disorders.

In the first report of a gene being responsible for speech and language, Lai et al. found that a single gene on chomosome 7 relates to brain circuitry involved in speech and language.45 Three generations of a family and an unrelated person had severe speech and language problems. A disrupted gene, FOXP2, with a guanine nucleotide substituted for an adenine, then transmits as an autosomal-dominant. Unaffected family members and other unaffected nonrelated persons have no such substitution.

Memory

Memory stores and recalls experience, helping with personal survival and necessary for sustained relationships and socialization. In the Middle Ages, its definition included many abilities now considered creativity. Two memory systems exist: declarative (explicit), featuring awareness of past experiences; and nondeclarative, without conscious awareness.46 An intact hippocampus and related structures mediate explicit memory; the dorsal and anterior thalamic nuclei and the mammillary bodies also play roles. The frontal lobes mediate working memory, or the temporary storage of information to perform a specific task. This places experience in context and allows memory search for many purposes. Two prefrontal areas, dorsolateral and orbitomedial, operate in working memory. Damage to the first impairs regulation and integration of cognition; damage to the latter impairs emotional and social functioning. Non-declarative memory fosters skills and habits, classical conditioning, and non-associative learning.

Humans and other species use face recognition as an important social task. For example, sheep remember both sheep and human faces for more than 2 years, distinguishing both the frontal and profile views, and human babies 21 days old can hold in memory the imitated model of a facial expression for at least 2.5 minutes. A small group of cells in the temporal and medial prefrontal cortices, particularly on the right, supports this specialized function.47 Episodic memory, or the recollection of one's personal past, appears at about age 4. The child becomes aware of self-experience over time. Memory consolidation occurs mainly during REM sleep, and dreams may serve a role in social adaptation. Better recollection occurs if one's mood state at the time of an experience recurs at the time of attempted retrieval.

New neurons form in adult mammalian brains, including monkeys and humans, in the olfactory bulb (smell) and the hippocampus (memory). Many birds add neurons throughout adulthood, specifically those involved in song production and memory.50 One factor regulating the neuronal replacement appears to be sensorimotor stimulation.48 Such neurogenesis decreases from stress, a boring environment, and perhaps depression. Story memory in humans associates with increased size of the left hippocampus. Human high cortisol levels during a 5-year period associate with 14% lower hippocampus volume, compared with those who have moderate cortisol levels.49 Lack of neurogenesis in olfactory bulb neurons may produce lessened olfactory identification as an early problem in Alzheimer's disease.

Therapeutic Implications of Social Brain Research

Delineating specific genetic and environmental roles in development will allow more accurate diagnoses of malfunction and interventions that support survival of the individual and of mankind. Massive amounts of genetic research increasingly delineate specific genetic chromosomal or metabolic entities. For some disorders, gene therapy holds promise; for example, neural stem cells may eventually treat patients with neurodegenerative disorders. Adult mouse brain stem cells have been isolated; these versatile cells produce both neurons and glia, and when plated on muscle-cell cultures, half produce muscle cells.51

Approximately 9% of physical disorders present with psychiatric symptoms, the most common being depression, anxiety, confusion, memory, and speech disorders. Some people with histories of Group A beta-hemolytic streptococcal infections display autoimmune problems presenting as obsessive-compulsive disorder, Syndenhan's chorea, or Tourette syndrome.2 The symptoms resemble idiopathic psychiatric entities, but post-infectious conditions respond to treatment with plasmaphoresis and antibiotics.

Leads to possible treatment for drug addiction have stemmed from rats given methylphenidate during preadolescence and then exposed to cocaine as adults. The mature rats responded less to cocaine, with increased aversion to it.52 However, if the rates were exposed to methylphenidate as adults, they responded less to cocaine but without the aversion. Thus, the developmental stage played a role in cocaine responsivity.

Stereotypes may lead to diagnostic errors, as might an undue emphasis on environment with little attention to personal or social factors. A person facing adverse personal and social conditions may seem flat or suspicious; some clinicians may see this alone as pathologic. Patients feeling “put down” do not long remain in treatment.21 For success, the therapist must find something likeable in the patient. As a therapist learns more about the reasons behind a patient's behavior, the therapist's attitude usually becomes more helpful and empathic.

Schools have been shown to play important roles in decreasing violence. Teaching and modeling socially appropriate behavior, adequate supervision on the playground, and no tolerance for predatory or bullying behavior decrease aggression and increase academic performance. Along with forbidding intimidating behavior, adults need to help children avoid watching such behavior and teach children to refuse to assume the victim role.

Altering individal behavior or a group environment is a long-term project requiring group incentives, education, and clear objectives. A problem's meaning typically reflects the group's beliefs. Understanding the cultural background helps tailor the approach used.28 For example, approved child punishment in one culture may constitute abuse in another.

Family therapists must demonstrate sensitivity to values and “agree to disagree” with the family if necessary. For example, black families respond to a short term, present-oriented, problem-solving approach, as when encouraging the family to solve its own problems,28 while Asian families benefit from formal, structured and practical assistance; indirect communication helps avoid shame. Therapists also should consider the potential support that stems from extended family.21

The changing roles of families need careful scrutiny, and informed, sensitive care plays a critical role when diagnosing or treating dysfunction in the family.22 Dual-career marriages often need help in communications, problem solving, conflict resolution, and time management. Teenage mothers who receive educational assistance are more likely to become self-sufficient. Pregnancy also may deter the education of a teenage father, making assistance required. Lesbian and gay families may need assistance in coping with societal reactions. Complex families can exhibit stressful interactions, and the family members may need to expand contacts to more than the immediate stepfamily to be satisfied with relationships. When adult children return home, effective rules help work out problems with household labor, family property, authority relationships, financial obligations, and communication.

Tolerance of differences can be taught and encouraged.22 In all cultures, people must be able to communicate with one another. Children of deaf or immigrant parents may become “language brokers” for their parents and “parentified” children. As interpreters for their parents, they may gain inappropriate exposure to intimate medical and legal issues in addition to more age-appropriate exchanges with hearing people. This expectation for the child becomes the norm in most families and must be challenged, especially regarding the inappropriate use of children for adult-only conversations.

Children in dysfunctional families learn not to express emotion so they feel nothing. They must be taught to be open, direct, and assertive. Women may over-function emotionally (responsible for everyone) and in communication by advising, rescuing, and taking over when stress occurs. They need to be helped to have a healthier mutual relationship.21 Men tend not to ask for help, become quite isolated, and may underestimate their distress. Therapists may have to reach out to them in an invitational manner. In our society, black men who have certain behavior problems are more likely than white men to be sent to the correctional system rather than the mental health system.21 Being aware of this practice is essential to ensure black men receive the diagnostic and treatment attention they need.

Work inhibition is now being seen more often in women, and men are seen more often for problems in relationships. Because of culturally induced value systems, the therapist may respond more to love-related problems of women and work-related problems of men. The male standard of what is “normal” has dominated our models of psychic experience.

The gender of the therapist does affect the beginning relationship and the early and evolving transference. Some recommend a same-sex therapist for adolescents because sexual issues are so intrusive at that stage of development, and this attraction can interfere with progress.21 Women are more likely than men to gain referrals for individual therapy, but men are more likely to get referrals to male therapists.

Some therapists routinely overlook some real-life issues such as male infertility, menstruation, physical illness, or sexual function because people are instructed at some time in their lives that these issues are “not discussed in polite society.” In a group situation, men are more likely to respond negatively to women leaders and positively to men leaders for saying the same thing. Early developmental issues may surface more in same-sex groups; mixed-sex groups may be helpful for issues of professional development.21

Summary

Addressing molecular-genetic pathogenesis of disorders seems more readily accomplished in our present era of considerable data production. These levels of analysis must be integrated into higher levels of analysis. For example, while attention often focuses on the rationale for use of medication, we also need to account for many other factors that affect the person's, the family's, and the group's views of dysfunction. Considering these factors, views and communication states take time, motivation, education, and consensus opinion to change. We must work integratively and will do this more productively with a social brain focus. Only with such integration will treatment plans achieve greater adequacy for the troubled people whom psychiatrists hope to help.

References

  1. Carroll S. Endless Forms Most Beautiful: The New Science of Evo Devo and the Making of the Animal Kingdom. New York, NY: W.W. Norton & Co. 2005.
  2. Leckman JF, Mayes LC. Understanding developmental psychopathology: how useful are evalutionary accounts?J Am Acad Child Adolesc Psychiatry. 1998;37(10):1011–1021. doi:10.1097/00004583-199810000-00010 [CrossRef]9785712
  3. Wilson EO. Consilience: The Unity of Knowledge. New York, NY: Vintage Books. 1999;107–277.
  4. Woods BT. Is schizophrenia a progressive neurodevelopmental disorder? Toward a unitary pathogenetic mechanism. Am J Psychiatry. 1998;155(12):1661–1670. doi:10.1176/ajp.155.12.1661 [CrossRef]9842773
  5. Allman JM. Evolving Brains (Scientific American Library). New York, NY: WH Freeman & Co. 1999.
  6. Harris J. Developmental Neuropsychiatry, Vol. 1: Fundamentals. New York, NY: Oxford University Press. 1995;128–242.
  7. Reiman EM. The application of positron emission tomography to the study of normal and pathologic emotions. J Clin Psychiatry. 1997;58(suppl16):4–12.9430503
  8. Greene JD, Sommerville RE, Nystrom LE, Darley JM, Cohen JD. An fMRI investigation of emotional engagement in moral judgment. Science. 2001;293(5537):2105–2108. doi:10.1126/science.1062872 [CrossRef]11557895
  9. Hamer DH. The heritability of happiness. Nat Genet. 1996;14(2):125–126. doi:10.1038/ng1096-125 [CrossRef]8841176
  10. Reiss D, Plomin R, Hetherington EM. Genetics and psychiatry: an unheralded window on the environment. Am J Psychiatry. 1991;148(3)283–291. doi:10.1176/ajp.148.3.283 [CrossRef]1992831
  11. Hagerman RJ, Jackson C, Amiri K, Silverman AC, O'Connor R, Sobesky W. Girls with Fragile X syndrome: physical and neurocognitive status and outcome. Pediatrics. 1992;89(3):395–400.1741210
  12. Schultz RT, Grelotti DJ, Pober B. Genetics of Childhood Disorders: XXVI, Williams syndrome and brain-behavior relationships. J Am Acad Child Adolesc Psychiatry. 2001;40(5):606–609. doi:10.1097/00004583-200105000-00022 [CrossRef]11349707
  13. Stern DN. A micro-analysis of mother-infant interaction. J Am Acad Child Adolescent Psychiatry. 1971;10(3):501–517. doi:10.1016/S0002-7138(09)61752-0 [CrossRef]
  14. Call J, Galenson E, Tyson RL. Frontiers of Infant Psychiatry, Vol II. New York, NY: Basic Books Inc. 1984;3–14,261–283,522–530.
  15. Zeanah CH, Boris NW, Larrieu JA. Infant development and developmental risk: a review of the past 10 years. J Am Acad Child Adolesc Psychiatry. 1997;36(2):165–178. doi:10.1097/00004583-199702000-00007 [CrossRef]9031569
  16. LeGrand R, Mondloch CJ, Maurer D, Brent HP. Neuroperception. Early visual experience and face processing. Nature. 2001;410(6831):890. doi:10.1038/35073749 [CrossRef]
  17. DeCasper AJ, Spence MJ. Prenatal maternal speech influences newborns' perception of speech sounds. Infant Behav Dev. 1986;9: 133–150. doi:10.1016/0163-6383(86)90025-1 [CrossRef]
  18. Mehler J, Jusczyk P, Lamberz A. A precursor to language development in young infants. Nature. 1994;37():292–294
  19. Sulloway Fl.Born to Rebel — Birth Order, Family Dynamics, and Creative Lives. New York, NY: Pantheon Books. 1996.
  20. McCandless BR. The socialization of the individual. In: Schopler E, Reichler RJ. Psychopathology and Child Development. New York, NY: Plenum Press; 1976:185–202. doi:10.1007/978-1-4684-2187-3_11 [CrossRef]
  21. Dickstein L. Perspectives on human development. In: Tasman A, Goldfinger SM. Review of Psychiatry, Vol. 10. Washington DC: American Psychiatric Publishing; 1991;531–647.
  22. Barinaga M. Social status sculpts activity of crayfish neurons. Science. 1996; 271(5247):290–291. doi:10.1126/science.271.5247.290 [CrossRef]8553060
  23. Jang KL, Vernon PA, Livesley WJ. Behavioural-genetic perspectives on personality function. Can J Psychiatry. 2001;46(3):234–244. doi:10.1177/070674370104600303 [CrossRef]11320677
  24. Mlot C. Probing the biology of emotion. Science. 1998;280(5366):1005–1007. doi:10.1126/science.280.5366.1005 [CrossRef]9616078
  25. In Brief: Bird brains. Sci Am. 1998;278(1):30. doi:10.1038/scientificamerican0198-30a [CrossRef]
  26. Roush W. Worm longevity gene cloned. Science. 1997;277(5328):942–946. doi:10.1126/science.277.5328.897 [CrossRef]
  27. Calhoun JB. Population density and social pathology. Sci Am. Feb1962;206:139–148.13875732
  28. Alarcon RD, ed. Cultural Psychiatry. Psychiatric Clinics of North America. Philadelphia, PA: WB Saunders & Co.; 1995.
  29. Whiten A, Goodall I, McGrew WD, et al. Cultures in chimpanzees. Nature. 1999;399: 682–685. doi:10.1038/21415 [CrossRef]10385119
  30. Manuck SB, Bliel ME, Petersen KL, et al. The socio-economic status of communities predicts variation in brain serotonergic responsivity. Psychol Med. 2005;35(4):519–528. doi:10.1017/S0033291704003757 [CrossRef]15856722
  31. Curie-Cohen M, Yoshihara D, Luttress L, et al. The effects of dominance on mating behavior and paternity in a captive troop of rhesus monkeys (Macaca mulatta). Am J Primatology. 1983;5:127–138. doi:10.1002/ajp.1350050204 [CrossRef]
  32. Wrangham RW. Subtle, secret female chimpanzees. Science. 1997;277(5327):774–775. doi:10.1126/science.277.5327.774 [CrossRef]9273699
  33. Diamond J. Guns, Germs, and Steel. New York, NY: WW Norton & Co; 1999:25–89.
  34. Meltzoff AN, Moore MK. Newborn infants imitate adult facial gestures. Child Dev. 1983; 54(3):702–709. doi:10.2307/1130058 [CrossRef]6851717
  35. Lembke A, Ketter TA. Impaired recognition of facial emotion in mania. Am J Psychiatry. 2002;159(2):302–304. doi:10.1176/appi.ajp.159.2.302 [CrossRef]11823275
  36. Rapoport J, Fiske A. The new biology of obsessive-compulsive disorder: implications for evolutionary psychology. Perspect Biol Med. 1998;41(2):159–175. doi:10.1353/pbm.1998.0063 [CrossRef]9493398
  37. Fiske AP, Haslam N. Is obsessive-compulsive disorder a pathology of the human disposition to perform socially meaningful rituals? Evidence of similar content. J Nerv Ment Dis. 1997;185(4):211–222. doi:10.1097/00005053-199704000-00001 [CrossRef]9114806
  38. Oota H, Settheetham-Ishida W, Tiwawech D, Ishida T, Stoneking M. Human mtDNA and Y-chromosome variation is correlated with matri-local versus patrilocal residence. Nat Genet. 2001;29(1):20–21. doi:10.1038/ng711 [CrossRef]11528385
  39. Nelson RJ, Demas GE, Huang PL, et al. Behavioural abnormalities in male mice lacking neuronal nitric oxide synthase. Nature. 1995;378(6555):383–386. doi:10.1038/378383a0 [CrossRef]7477374
  40. Twemlow SW, Fonagy P, Sacco FC, Gies ML, Evans R, Ewbank R. Creating a peaceful school learning environment: a controlled study of an elementary school intervention to reduce violence. Am J Psychiatry. 2001;158(5):808–810. doi:10.1176/appi.ajp.158.5.808 [CrossRef]11329408
  41. Lieberman P. Peak capacity. The Sciences. Nov–Dec1997;22–27. doi:10.1002/j.2326-1951.1997.tb03815.x [CrossRef]
  42. Dunbar R. Grooming, Gossip, and the Evolution of Language. Cambridge, MA: Harvard University Press; 1996;62–69.
  43. Toppelberg CO, Shapiro T. Language disorders: a 10-year research update review. J Am Acad Child Adolesc Psychiatry. 2000; 39(2):143–152. doi:10.1097/00004583-200002000-00011 [CrossRef]10673823
  44. Beitchman JH, Wilson B, Johnson CJ, et al. Fourteen-year follow-up of speech/language-impaired and control children: psychiatric outcome. J Am Acad Child Adolesc Psychiatry. 2001,40(1):75–82. doi:10.1097/00004583-200101000-00019 [CrossRef]11195567
  45. Lai CS, Fisher SE, Jurst JA, Vargha-Khadem F, Monaco AP. A forkhead-domain gene is mutated in a severe speech and language disorder. Nature. 2001;413(6855):519–523. doi:10.1038/35097076 [CrossRef]11586359
  46. Goldman RS, Smet IC, Singh M. Cognitive neuroscience: learning and memory. In: Kay J, Tasman A, Lieberman JA (eds). Psychiatry 2000. Philadelphia, PA: WE Saunders; 2000:161–170.
  47. Kendrick KM, da Costa AP, Leigh AB, Hinton MR, Peirce JW. Sheep don't forget a face. Nature. 2001;414(8):165–166. doi:10.1038/35102669 [CrossRef]11700543
  48. Naegele JR, Lombroso PJ. Genetics of central nervous system developmental disorders. Child Adolesc Psychiatr Clin N Am. 2001; 10(2):225–239. doi:10.1016/S1056-4993(18)30055-5 [CrossRef]11351796
  49. Lupien SJ, de Leon M, de Santi S, et al. Cortisol levels during human aging predict hippocampal atrophy and memory deficits. Nat Neurosci. 1998,1(1):69–73. doi:10.1038/271 [CrossRef]
  50. Macklis JD. Neurobiology: New memories from new neurons. Nature. 2001;410(6826): 314–315, 317. doi:10.1038/35066661 [CrossRef]11268187
  51. Rietze RL, Valcanis H, Brooker OF, Thomas T, Voss AK, Bartlett PF. Purification of a pluripotent neural stem cell from the adult mouse brain. Nature. 2001;412(6848):736–739. doi:10.1038/35089085 [CrossRef]11507641
  52. Andersen SL, Arvanitogiannis A, Pliakas AM, LeBlanc C, Carlezon WA Jr, . Altered responsiveness to cocaine in rats exposed to methylphenidate during development. Nat Neurosci. 2002;5(1):13–14. doi:10.1038/nn777 [CrossRef]

Educational Objectives

  1. List ways brain and genetics research bears on social behavior, language, and memory.

  2. Describe treatment plan modifications needed for newly evolved nontraditional family structures.

  3. Discuss findings wherein behavioral/social findings on nonhuman animals bear on human sociality.

Authors

Dr. Sutton is chairman, Research Committee, Group for the Advancement of Psychiatry, and director, Child and Adolescent Psychiatry Training Program, Austin Medical Education Programs, Austin TX.

Address reprint requests to: Beverly J. Sutton, MD, Seton Healthcare Network, Seton Shoal Creek Hospital, 3501 Mills Avenue, Austin, TX 78731; or e-mail bsutton@seton.org.

Dr. Sutton has disclosed no relevant financial relationships.

10.3928/00485713-20051001-04

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