Chapters 8-16

spermarche

A boy's first ejaculation.

asthma

A chronic respiratory disease characterized by sudden attacks of coughing, wheezing, and difficulty in breathing.

menarche

A girl's first menstruation.

growth spurts

ADOLESCENT GROWTH SPURT - Sharp increase in height and weight that precedes sexual maturity.

Parenting Styles

AUTHORITARIAN - parenting emphasizes control and unquestioning obedience. Authoritarian parents try to make children conform rigidly to a set standard of conduct and punish them for violating it, often using power-assertive techniques. They are more detached and less warm than other parents. Their children tend to be more discontented, withdrawn, and distrustful. PERMISSIVE- parents make few demands and allow children to monitor their own activities as much as possible. They are warm, non-controlling, and undemanding or even indulgent. Their preschool children tend to be immature - the least self-controlled and the least exploratory. AUTHORITATIVE - parents respect children's independent decisions, interests, opinions, and personalities. They are loving and accepting but also demand good behavior and are firm in maintaining standards. They impose limited, judicious punishment when necessary, within the context of a warm, supportive relationship. They favor inductive discipline, explaining the reasoning behind their stand and encouraging verbal negotiation and give and take. Their children apparently feel secure in knowing they are loved and what is expected of them. These preschoolers tend to be the most self-reliant, self-controlled, self-assertive, exploratory and content. NEGLECTFUL OR UNINVOLVED - those parents focus on their own needs rather than on those of the child. Neglectful parenting has been linked with a variety of behavioral disorders in childhood and adolescence.

Social Construction

Adolescence is a social construction. In preindustrial societies, children entered the adult world when they matured physically or when they began a vocational apprenticeship.

Brain & Prefrontal Cortex

Adolescents process information differently than adults do. To understand the immaturity of the adolescent brain, we need to look at changes in the structure and composition of the frontal cortex. First, a steady increase in white matter, nerve fibers that connect distant portions of the brain, permits faster transmission of information. In adolescence, this process continues in the frontal lobes. In addition, there is a major spurt in production of gray matter int the frontal lobes. Second, the pruning of unused dendritic connections during childhood results in a reduction in density of gray matter, or nerve cells, thus increasing the brain's efficiency. This process begins in the rear portions of the brain and moves forward. Thus, by mid- to late adolescence young people have fewer but stronger, smoother, and more effective neuronal connections, making cognitive processing more efficient. However, this process takes time, and for the most part it has not yet reached the frontal loves by adolescence. Underdevelopment of frontal cortical systems associated with motivation, impulsivity, and addiction may help explain why adolescents tend to seek thrills and novelty and why many of them find it hard to focus on long-term goals.

family and peer relationships

Age becomes a powerful bonding agent in adolescence. Adolescents spend more time with peers and less with family. However, most teenagers' fundamental values remain closer to their parents' than is generally realized. Even as adolescents turn to peers for role models, companionship, and intimacy, they still look to parents for secure base from which they can try their wings.

bullying

Aggression deliberately and persistently directed against a particular target, or victim, typically one who is weak, vulnerable, and defenseless.

OCD

Anxiety aroused by repetitive, intrusive thoughts, images, or impulses, often leading to compulsive ritual behaviors.

Pro-social Behavior

Any voluntary behavior intended to help others.

moral development

As children grow older and attain higher cognitive levels, they become capable of more complex reasoning about moral issues. Their tendencies toward altruism and empathy increase as well. Adolescents are better able than younger children to take another person's perspective, solve social problems, deal with interpersonal relationships, and see themselves as social beings. Level I: PRE-CONVENTIONAL MORALITY - people at under external controls. They obey rules to avoid punishment or reap rewards, or they act out of self-interest. (This level is typical of children ages 4 to 10) Level II: CONVENTIONAL MORALITY - People have internalized the standards of authority figures. They are concerned about being "good" pleasing others, and maintaining the social order. (This level is typically reached after age 10) Level III: POST-CONVENTIONAL MORALITY - People recognize conflicts between moral standards and make judgments on the basis of principles of right, fairness, and justice. People generally do not reach this level of moral reasoning until at least early adolescence, or more commonly in young adulthood, if ever.

Parenting

As children increasingly become their own persons, their upbringing can be a complex challenge. Parents must deal with small people who have minds and wills of their own, but still have a lot to learn about what kinds of behavior work well in society. Two areas that impact child development are forms of discipline and parenting styles.

advances of preoperational stage terms

As children's cognitive development proceeds, they begin to think in fundamentally different ways. Young children are grounded in the concrete here and now, according to Piaget, and the fundamental achievements in cognitive ability stem from fundamental achievements in cognitive ability stem from advances in symbolic thought. These advances are accompanied by a growing understanding that was previously impossible of objects in space, causality, identities and categorization, and number.

theory of mind

Awareness and understanding of mental processes of others.

Gender Constancy

Awareness that one will always be male or female. Also called se category constancy.

Gender-Identity

Awareness, developed in early childhood, that one is male or female.

Gender Roles

Behaviors, interests, attitudes, skills, and traits that culture considers appropriate for each sex, differs for males and females.

Obesity

Body mass index over 95 percentile. In the U.S. about 17% of children between 2 and 19 are obese and another 16.5 % are overweight. Boys are more likely to be overweight than girls. Although the number of overweight children has increased in all ethnic groups, it is most prevalent among Mexican American boys and non-Hispanic black girls.

Brain Development

Changes in the brain's structure and functioning support the cognitive advances of middle childhood. Maturation and learning in middle childhood and beyond depend on fine-tuning the brain's connections. For example, as children age, areas of their brains become increasingly specialized for particular tasks. These changes increase the speed and efficiency of brain processes and enhance the ability to filter out irrelevant information.

information processing

Changes in the way adolescents process information reflect the maturation of the brain's frontal lobes and may help explain the cognitive advances. Piaget described. Which neural connections wither and which become strengthened are highly responsive to experience. Thus progress in cognitive processing varies greatly among individual adolescent. Researchers have identified two broad categories of measurable change in functional change. DECLARATIVE KNOWLEDGE - "knowing that....." PROCEDURAL KNOWLEDGE - "knowing how to...." CONCEPTUAL KNOWLEDGE - "knowing why"

motor development

Children ages 3-6 makes great advances in motor skill developments- both gross motor skills such as running and jumping, which involve the large muscles, and fine motor skills, which are manipulative skills such as buttoning and drawing that involve eye-hand and small muscle coordination. They also begin to show a preference for using either the right or left hand.

language development

Children's use of language generally reflects their level of cognitive development. School-age children are quite proficient in use of language, but adolescence brings further refinements. Vocabulary continues to grow as reading matter becomes more adult. By ages 16-18 the average young person knows approximately 80,000 words.

Self definition

Cluster of characteristics used to describe oneself

Adolescence

Developmental transition between childhood and adulthood entailing major physical, cognitive, and psychosocial changes.

STDs

Diseases spread by sexual contact. Hpv, chlamydia, gonorreah, genital herpes, trichomoniasis and HIV

anorexia

Eating disorder characterized by self-starvation and extreme weight loss.

bulimia

Eating disorder in which a person regularly eats huge quantities of food and then purges the body by laxatives, induced vomiting, fasting, or excessive exercise.

Social Emotions

Emotions directed at the self that involve a comparison of oneself or one's actions to social standards.

identity vs. identity confusion (Erickson)

Erickson fifth stage of psychosocial development in which an adolescent seeks to develop a coherent sense of self, including the role she or he is to play in society. Also called identity vs. role confusion.

gender-identity

Erikson's view that, for women, identity and intimacy develop together. Rather than view this pattern as a departure from a male norm, however, some researchers see it as pointing to a weakness in Erikson's theory, which, they claim, is based on male-centered Western concepts of individuality, autonomy, and competitiveness. According to Carol Gilligan, the female sense of self develops not so much through achieving a separate identity as through establishing relationships. Girls and women, says sibilities and on their ability to care for others as well as for themselves. In research on Marcia's identity statuses, however, few gender differences have appeared.

Cognitive Levels of Play

FUNCTIONAL PLAY - lowest cognitive level of play, involving repetitive muscular movements; also called locomotor play. CONSTRUCTIVE PLAY - Second cognitive level of play, involving use of objects or materials to make something, also called object play. DRAMATIC PLAY - Play involving imaginary people or situations; also called fantasy play, pretend play or imaginative play. FORMAL GAMES WITH RULES - Organized games with known procedures and penalties.

influences

Family and school experiences are subject to a phenomenon referred to as spillover, wherein experiences in difference contexts influence each other. Stress at home has been shown to predict problems with attendance and learning; conversely, problems with attendance and learning contribute to family stress.

EC education and school types

Going to preschool around age 3 is an important step that widens a child's physical, cognitive, and social environment. The transition to kindergarten, the beginning of "real school," at age 5 is another momentous step. Preschool enrollments have increased dramatically over the last 20 years, and approximately 57% of preschool children are enrolled in some form of center-based childcare setting.

hypertension

High blood pressure

identity/ orientation

In Erikson's terminology, a coherent conception of the self made up of goals, values, and beliefs to which a person is solidly committed. The prevalence of homosexual orientation varies widely, depending on how it is defined and measured. Depending on whether it is measured by sexual, or romantic, attraction or arousal, by sexual behavior, or by sexual identity, the rate of homosexuality in the U>S> population ranges from 1-15%.

Identification

In Freudian theory, process by which a young child adopts characteristics, beliefs, attitudes, values, and behaviors of the parent of the same sex.

transduction

In Piaget's terminology, pre-operational child's tendency to mentally link particular experiences, whether or not there is logically a causal relationship.

centration

In Piaget's theory, tendency of pre-operational children to focus on one aspect of a situation and neglect others.

preoperational stage

In Piaget´s theory, the second major stage of cognitive development in which children become more sophisticated in their use of symbolic thought but are not yet able to use logic. PIAGETIAN APPROACH: called early childhood the pre-operational stage of cognitive development because children of this age are not ready to engage in logical mental operations. This period is characterized by a great expansion in the use of symbolic thought, or representational ability, which first emerges near the end of the sensorimotor stage, and is most notably illustrated by the growth of language abilities. In this section we look at advances and immature aspects of pre-operational thought as well as the development of theory of mind.

Social and Non-Social Play (Gender and Cultural Influence of play)

In a classic study done in 1920s, Mildred Parten, identified six types of play ranging from the least to the most social. She found that as children get older, their play tends to become more social, that is, more interactive and more cooperative. At first, children play alone, then alongside other children, and finally together. Today, however, many researchers view Parten's characterization of children's play development as too simplistic, as children of all ages engage in all of Parten's categories of play. Parten apparently regarded non-social play can sometimes be a sign of shyness, anxiety, fearfulness, or social rejection, it is more likely that some children just prefer to play by themselves. For instance, in one study of 567 kindergarteners, almost 2 out of 3 children who played alone were rated as socially and cognitively competent.One kind of play that becomes more social during the preschool years is dramatic play. Children typically engage in more dramatic play when playing with someone else than when playing alone. As dramatic play becomes more collaborative, story lines become more complex and innovative, offering rich opportunities to practice interpersonal and language skills and to explore social conventions and roles.

Sluttering

Involuntary, frequent repetition or prolongation of sounds or syllables.

Class Inclusion

Is the ability to see the relationship between a whole and its parts. Piaget (1964) showed pre-operational children a bunch of 10 flowers 7 roses and 3 carnations and asked whether there were more roses or more flowers. The children tended to say there were more roses because they were comparing the roses with the carnations rather than with the whole bunch. Not until age 7-8 and sometimes not even then, do children consistently reason that roses are a subclass of flowers and than flowers.

Self Esteem

Judgment a person makes about his or her self-worth.

Language

Language abilities continue to grow during middle childhood. School-age children become better at understanding and interpreting oral and written communication and making themselves understood.

Chronic Medical Conditions

Long-lasting or recurrent physical, developmental, behavioral, and or emotional conditions that require special health services.

delinquency

Many teenagers engage in some degree of antisocial or delinquent behavior. In this following section, we outline some of the factors that influence these behaviors.

Health and Safety

Middle childhood is a relatively safe period in the life span, and in the modern world most children enjoy good healthy. However, while the death rate in the middle childhood years is the lowest in the life span, the increasingly sedentary nature of modern life combined with the easy availability of high-calorie food has resulted in an epidemic of overweight and obesity in the United States. Moreover, some children suffer from chronic medical conditions, accidental injuries, lack of access to healthy care, or emotional disturbances.

Types of Preschools

Montessori - Montesorrori stresses the importance of children learning independently at their own pace in multiage-classrooms as they work with developmentally appropriate materials and self-chosen tasks. Teachers serve as guides, and older children help younger ones. An evaluation of Montessori education in Milwaukee found that 5 year old Montessori students were better prepared for elementary school in reading and math than children who attended other types of preschools. and Reggio Emilia Methods - named for the town in Italy in which the movement first started in the 1940s, is a less formal model than Montessori, Children are highly valued, considered capable, and given the opportunity to explore what they desire. Teachers follow children's interest and support them in exploring and investigating ideas and feelings through words, movement, dramatic play, and music. Learning is purposeful but less defined than with the Montessori curriculum. Teachers ask questions that draw out children's ideas and then create flexible plans to explore these ideas with the children. Classrooms are carefully constructed to offer complexity, beauty, organization, and sense of well-being. Project Head Start - Many children in poor areas in the United States enter school unprepared to learn. Since the 1960, large-scale programs have been developed to help such children compensate for what they have missed and to prepare them for school. Universal Preschool - A national system for early care and education that makes access to preschool similar to kindergarten by using the public schools

Childhood depression

Mood disorder characterized by such symptoms as a prolonged sense of friendlessness, inability to have fun or concentrate, fatigue, extreme activity or apathy, feelings of worthlessness, wight change, physical complaints, and thoughts of death or suicide.

teen pregnancy

More than 4 on 10 adolescent girls in the United States have been pregnant at least once before age 20. More than half (51%) of pregnant teenagers in the U.S. have their babies, and 35% choose to abort. 14% of teen pregnancies end in miscarriage or stillbirth.

Altruism

Motivation to help others without expectation of reward; may involve self-denial or self-sacrifice.

Motor Development & Physical play

Motor skills continue to improve in middle childhood. By this age, most children in developing countries go to work, and this leaves them little time and freedom for physical play. However, play is an important context for physical and psychological health. In the United States, there has been a trend toward decreasing recess time for elementary schoolchildren, and more generally, toward more sedentary activities. At the same time, many children participate in organized sports. How do these physical activities or lack of them shape development?

Sleep disturbances

NIGHT TERRORS- appears to awaken abruptly from a deep sleep early in the night in a state of agitation. The child may scream and sit up in bed, breathing rapidly and staring or thrashing about. Yet he is not really awake. He quiets down quickly and remembers nothin about the episode the next morning. Night terrors generally peak between 2.5 to 4 years of age and decline thereafter; some researchers believe they are related to anxiety. Prevalence estimates of night terrors vary widely, and range from approximately 6 to almost 40% of children. SLEEP WALKING- Walking and talking during sleep are faily common in early and middle childhood. It is estimated that approximately 9% of children between ages 3-10 slepp walk, and a full 37% sleeptalk. Sleepwalking and sleeptalking are generally harmless, and their frequency declines as children age. It is best not to interrupt sleepwalking or night terrors because interruption may confuse and further frighten the child. Rather, the child can be quietly guided back to their room and tucked in to sleep. NIGHTMARES- are common during early childhood. They usually occur toward morning and are often brought on by staying up too late, eating a heavy meal close to bedtime, or overexcitement for example, watching an action-packed television program, seeing a terrifying movie, or hearing a frightening bedtime story. An occasional bad dream is no cause for alarm, but frequent or persistent nightmares, especially those that make a child fearful or anxious during walking hours, may signal excessive stress.

Nutrition and Sleep

NUTRITIONAL NEEDS - Schoolchildren need, on average, 2400 calories every day , for older children and less for younger ones. Nutritionists recommend a varied diet, including plenty of grains, fruits, and vegetables, and high levels of complex carbohydrates found in potatoes, pasta, bread, and cereals. SLEEP - Sleep needs decline from about 11 hrs. a day at age 5 to little more than 10 hrs. at age 9 and about 9 hrs. at age 13. Even so, many US children get less sleep than they need. Sleep problems, such as resistance to going to bed, insomnia, and daytime sleepiness are common during these years, in part because many children are allowed to set their own bedtimes as they grow older.

health and safety

OBESITY UNDERNUTRITION FOOD ALLERGIES ORAL HEALTH ACCIDENTAL INJURIES AND DEATHS ENVIRONMENTAL INFLUENCES ON HEALTH EXPOSURE TO SMOKING, AIR POLLUTION, PESTICIDES, AND LEAD

Acute Medical

Occasional illnesses that last a short time.

Diabetes

One of the most common diseases of childhood. It is characterized by high levels of glucose in the blood as a result of defective insulin production, ineffective insulin action, or both.

sex characteristics

PRIMARY SEX CHARACTERISTICS - organs directly related to reproduction, which enlarge and mature during adolescence. SECONDARY SEX CHARACTERISTICS - physiological signs of sexual maturation (such as breast development and growth of body hair) that do not involve the sex organs.

irreversibility

Piaget's term for a pre-operational child's failure to understand that an operation can go in two or more directions.

egocentrict

Piaget's term for an inability to consider another person's point of view, a characteristic of young children's thought.

conservation

Piaget's term for awareness that two objects that are equal according to a certain measure remain equal in the face of perceptual alteration so long as nothing has been added to or taken away from either object.

Piaget's Theory Formal Operation

Piaget's theory, final stage of cognitive development, characterized by the ability to think abstractly.

Concrete Operational

Piagetian Approach: The concrete Operational Child - At about age 7, according to Piaget, children enter the stage of concrete operations and begin to use mental operations to solve concrete (actual) problems. Children now can think logically because they can take multiple aspects of a situation into account. However, their thinking is still limited to real situations int the here and now. Children in the stage of concrete operations can perform many tasks at a much higher level than they could in the pre-operational stage. They have a better understanding of spatial concepts, causality, categorization, inductive and deductive reasoning, conservation, and number.

pretend play

Play involving imaginary people or situation; also called fantasy play, dramatic play, or imaginary play.

Gender Stereotypes (five perspectives of gender development)

Pre conceived generalizations about male or female role behavior.

Puberty

Process by which a person attains sexual maturity and the ability to reproduce.

retrievel

Process by which information is accessed or recalled from memory storage.

encoding

Process by which information is prepared for long-term storage and later retrieval.

enuresis

Repeated urination in clothing or in bed (this in not unusual). About 10-15% of 5 yr old, more commonly boys, wet the bed regularly, often while sleeping deeply. More than half outgrow bed-wetting by age 8 without special help. Preschool children normally recognize the feeling of full bladder while sleep and awaken to empty it. Children who wet the bed do not yet have this awareness. Enuresis runs in families, suggesting that genetics may play a role. A gene linked to enuresis points to heredity as a major factor, possibly in combination with slow motor maturation, sleep apnea, allergies, or poor behavioral control. About 75% of bed-wetters have a close relative who also wets the bed, and identical twins are more concordant than fraternal twins. Enuresis that persist beyond age 8-10 may be related to poor self concept or other psychological problems.

alcohol and drug abuse

Repeated, harmful use of a substance, usually alcohol or other drugs.

storage

Retention of information in memory for future use.

memory types

SENSORY MEMORY- Initial, brief, temporary storage of sensory information. WORKING MEMORY- Short-term storage of information being actively processed. EXECUTIVE FUNCTION- Conscious control of thoughts, emotions, and actions to accomplish goals or solve problems. CENTRAL EXECUTIVE- In Baddeley's model, element of working memory that controls the processing of information. LONG-TERM MEMORY- Storage of virtually unlimited capacity that holds information for long periods. RECOGNITION- Ability to identify a previously encountered stimulus. RECALL- Ability to reproduce material from memory.

education

School is a central organizing experience in most adolescents' lives. It offers opportunities to learn information, master new skills, and sharpen old skills; to participate in sports, the arts, and other activities; to explore vocational choices; and to be with friends. It widens intellectual and social horizons. Some adolescents, however, experience school not as an opportunity but as one more hindrance on the road to adulthood.

sexuality

Seeing oneself as a sexual being, recognizing one's sexual orientation, coming to terms with sexual stirrings, and forming romantic or sexual attachments are all part of achieving sexual identity. Awareness of sexuality is an important aspect of identity formation, profoundly affecting self-image and relationships

career choices

Self efficacy beliefs help shape the occupational options students consider and the way they prepare for careers. In addition, parents' values with regard to academic achievement influence adolescents' values and occupational goals.

Self Concept

Sense of self; descriptive and evaluative mental picture of one's abilities and traits

body image

Sometimes a determination not to become overweight can result result in problems more serious than overweight itself. Concern with body image may lead to obsessive efforts at weight control. This pattern is more common among girls than boys.

depression and suicide

Suicide is the fourth leading cause of death among U.S. 15 to 19 years olds. The teenage suicide rate fell by 34% between 1990 and 2006, however, the suicide rate shot back up by 8% its highest level in 15 years, with the largest increases among teenage girls. Hanging surpassed handguns as the preferred method among girls, but boys remained more likely to use firearms.

Scaffolding

Temporary support to help a child master a task.

technology \

The expansion of technology and the major role it plays in children's lives has affected learning. Research has indicated that while critical thinking and analysis skills have declined as a result of the increased use of computers and video games, visual skills have improved. Students are spending more time multitasking with visual media and less time reading for pleasure. Reading develops vocabulary, imagination, and induction, skills critical to solving more complex problems. Multitasking can prevent a deeper understanding of information. In one study students who were given access to the Internet during class did not process what was presented as well and performed more poorly than students without access.

friendships

The intensity and importance of friendships and the amount of time spent with friends are probably greater in adolescence than at any other time in the life span. Friendships tend to become more reciprocal, more equal, and more stable. Those that are less satisfying become less important or are abandoned.

gender-schema theory

Theory that children socialize themselves in their gender roles by developing a mentally organized network of information about what it means to be male or female in a particular culture.

secular trend

Trend that can be seen only by observing several generations, such as the trend toward earlier attainment of adult height and sexual maturity, which began a century ago.

opportunities and risky behavior

Two major concerns about adolescent sexual activity are the risks of contracting sexually transmitted infection and for heterosexual activity, of pregnancy. Most at risk are young people who start sexual activity early, have multiple partners, do not use contraceptives regularly, and have inadequate information or misinformation about sex. Other risk factors are living in a socioeconomically disadvantaged community, substance use, antisocial behavior, and association with deviant peers.

Rough and Tumble

Vigorous play involving wrestling, hitting, and chasing, often accompanied by laughing and screaming.

areas of language development

Vocabulary- this rapid expansion of vocabulary may occur through fast mapping, which allow a child to pick up the approximate meaning of a new word after hearing it only once or twice in conversation. From the context, children seem to form a quick hypothesis about the meaning of the word, which then is refined with further exposure and usage. Grammar and Syntax- The ways children combine syllables into works, and word into sentences, grow increasingly sophisticated during early childhood. At age 3, children typically begin to use plurals, possessives, and past tense, and they know the difference between I, you, and we. They can ask - and answer - What and where questions. However, their sentences are generally short, simple, and declarative ("Kitty wants milk") 4 yr. olds use complex, multi-clause sentences ("I'm eating because I'm hungry") Children 5-7, children's speech has become quite adult like . Pragmatics and Social Speech- Practical knowledge needed to use language for communicative purposes

literacy

What is the link between language and literacy? Language is necessary for literacy, but it is by no means enough. Social interaction promotes emergent literacy. As children learn the skills they will need to translate the written word into speech, they also learn that writing can express ideas, thoughts, and feelings. Preschool children often pretend to write through drawings or scribbles. Later represent words, syllables, or phonemes. Often their spelling is so inventive they themselves cannot read it. Reading to children is one of the most effective paths of literacy. 55% of United States children age 3 to 5 and not in kindergarten are read to daily by a family member. Children read to from an early age learn that reading and writing in English move from left to right and from top to bottom and that words are separated by spaces. They also are motivated to learn to read.

Information-Processing Approach: Memory Development

When recalling events, young children tend to focus on exact details, while simultaneously failing to notice important aspects of a situation, such as when and where an event occurred. However, as they improve in attention and in the speed and efficiency of information processing, their memories also improve, and they begin to form long-lasting memories more focused on the "gist" of what happened. In the following section, we summarize key changes that occur from ages 3 to 6 in the processes.

language development

Young children's growing facility with language helps them express their unique view of the world. Between ages 3-6 children make rapid advances in vocabulary, grammar and syntax, and pragmatics and social speech.

ZPD

Zone of Proximal Development- Vygotsky's term for the difference between what a child can do alone and what the child can do with help.

The brain

by age 3 the brain is approximately 90% of adult weight. The density of synapses in the prefrontal cortex peaks at age 4. Myelination of pathways for hearing is also complete around that age. By age 6, the brain has attained about 95% percent of its peak volume. However, wide individual differences exist. Two healthy, normally functioning children of the same age could have as much as a 50% difference in brain volume. From age 3'6, rapid brain growth occurs in the frontal areas that regulate planning and organizing actions. From ages 6'11, the most rapid growth is in an area that primarily supports associative thinking, language, and spatial relations. During early childhood, a gradual change occurs in the corpus callosum, a thick band of nerve fibers that links the left and right hemispheres. Progressive myelination of fibers in the corpus callosum permits more rapid transmission of information and better integration between the hemispheres. This development, which continues until age 15, improves such functions as coordination of the senses, memory processes, attention and arousal, and speech and hearing.

handedness

the preference for using one hand over the other, is usually evident by about age 3. Handedness is not always clear-cut; not everybody prefers one hand for every task. Boys are more likely to be left-handed than are girls. For every 100 left-handed girls there are 123 left-handed boys. Is handedness genetic or environmental? The answer is controversial. Some researchers argue that the environment must be more important since such factors as low birthweight and difficult deliveries are related to increased likelihood of left-ghhandedness.