We've talked about your ability to sense, learn, and think, but not all of these abilities are fully formed when you are born.
The processes that enable human beings to realize their potential are being investigated by developmental psychology.
In this chapter, we'll look at how people change from conception to adulthood.
Nature and nurture are two types of factors that influence human development.
Most psychologists recognize that nature and nurture work together in human development, despite some views that only one of these factors is important.
Many human behaviors are learned from experience of an external environment.
Human beings are able to learn because of their unique brain structures.
The products of both genetic and environmental factors are found in these structures.
You won't find a map of your brain in your genes.
Your genes are a recipe for making you, but the end product depends on how the recipe gets followed.
The boundaries that define the minimum and maximum values for many of your characteristics are provided by your genes.
When you're finished growing, your genes set a limit on how tall you can be.
The range of reaction is the space between the boundaries.
The environment determines where you end up.
For instance, if an individual is suffering from malnutrition or serious illness during their development, they may be put at the lower edge of their range of reaction for height, while sound nutrition and good health will push them higher.
The differences in intelligence and personality between identical twins are due to the fact that many psychological characteristics have ranges of reaction.
The twin study is a method of determining the relative contributions of genetic and environmental factors to the development of a trait.
See more about this type of research.
You mark the years that have passed since you were born when you calculate your age.
You had nine months of significant development before you were born.
Fetal development begins with conception and ends with birth.
A sperm and a female sex cell are combined into an egg.
There are three stages of gestation.
The two-week period following conception is the germinal stage.
The second stage lasts from the second week of development until about the eighth week.
The fetus is in the fetal stage from the ninth week until birth.
The fetal stage is when brain cells begin to generate axons and dendrites.
They begin to undergo myelination, the formation of a sheath around axons, which provides insulation and speeds up signal conduction.
The process of myelination doesn't happen at a constant rate in all areas of the brain after birth.
A newborn's brain is only 25% the size of an adult's, so much of its development occurs after birth.
The health of a child can be affected by what a mother is exposed to during her pregnancies.
The embryo is vulnerable to teratogens, substances that can lead to birth defects.
Fetal alcohol syndrome can be caused by the consumption of alcohol during pregnancy.
Fetal alcohol syndrome is characterized by reduced brain size, cognitive disabilities, and distinctive facial features.
Tobacco can cause lowered birth weight and perceptual and attentional deficits.
Heavy metals include lead and mercury.
Other sources can cause birth defects.
Fetal development can be hampered by infections, exposure to radiation, and deficiencies in nutrition.
When it comes to nutrition, mothers who are starving are more likely to give birth to children with deficits.
Even if a mother is well-fed, she can still be deficient in certain essential vitamins, such as iron and zinc, which can lead to birth defects.
Motor development is the emergence of the ability to walk, crawl, reach, and roll.
Around the same age, most infants begin life with innate reflexes and motor abilities.
Neonates are born with a small set of reflexes that are triggered by sensory stimulation.
As the infant develops more advanced motor skills, many of the reflexes present at birth eventually disappear.
The rooting and sucking reflexes are two of the most common infant reflexes.
An infant's sucking reflexes are caused by any object that enters its mouth.
The reflexes allow a newborn to find its mother's nipple and begin feeding, which is crucial for the infant's survival.
The grasping and Moro reflexes are believed to help a newborn thrive.
The infant's arms are extended and drawn in as if embracing.
The baby may have developed a way to cling to its mother.
The grasping reflex is the vigorous grasping of an object.
The baby's hand muscles are thought to be prepared for voluntary grasping in the months to come.
Some newborn reflexes have different purposes.
The Babinski reflex is the projection of the big toe and fanning of the other toes when the sole of the foot is touched.
Between the ages of 12 months and 2 years, infants lose their reflexes.
The toes on the sole of a child's foot are covered by the plantar reflex after that point.
The Babinski reflex is a sign of pathology.
Motor skills development usually follows two general rules.
The cephalocaudal rule describes the tendency for motor skills to emerge in sequence from the head to the feet.
An infant will control his head, trunk, and feet first.
The proximodistal rule describes the tendency for motor skills to emerge in sequence from the center to the periphery.
An infant first gains control of her trunk, followed by her hands and feet.
Babies are unable to survive without their caregivers.
It's clear that food, shelter, and safety are important for an infant's survival, but they're also important for an emotional bond.
The psychological development of an infant is affected by the attachment it forms with its caregivers.
Babies who were living in orphanages were studied by psychologists during World War II.
Despite the fact that these children had shelter, warmth, safety, and food, many grew up to be physically and mentally retarded.
Harry Harlow studied social isolation in rhesus monkeys.
When rhesus monkeys were socially isolated for the first six months of their lives, they developed a variety of problems, such as difficulty communicating or learning from others.
The females from the experiment who went on to become mothers were ignored, rejected, and even attacked their own babies.
One mother was made of wire and the other was soft cloth.
The rhesus monkeys spent most of their time clinging to the cloth mother, despite the fact that the wire mother provided food.
Harlow concluded that the need for affection was more important than the need for food.
Konrad Lorenz's discovery of the process of "imprinting" in geese and other species contributed to the study of attachment.
Lorenz noticed that goslings form an instinctive attachment to the first moving object they encounter after hatching, following the object wherever it goes.
While human beings don't observe imprinting, it shows a form of attachment found in some nonhuman animals.
John Bowlby wanted to understand how human infants formed bonds to their caregivers.
Humans are born without the ability to physically follow their caregivers.
Human babies have developed an alternative strategy: they cry, coo, gurgle, and smile.
Most adults move toward a baby because of these actions.
Bowlby claimed that infants send signals to people who are close to them and that they keep a mental tally of who responds the most often.
They begin to target the majority of their signals to their primary caregivers.
A baby may feel secure playing in the room, but then cry and become distressed when its primary caregivers leaves.
Bowlby said that infants are prone to form emotional bonds with their primary caregivers.
An internal working model of attachment is a set of expectations an infant forms about how its primary caregivers will respond to it.
There are different attachment styles developed on the basis of these models.
The Strange Situation test can be used to determine what type of attachment an infant has.
A stranger is with the caregivers and infant.
The caregivers leaves, the infant and stranger remain.
The infant is alone.
There are 3 different attachment styles.
Other researchers identified a disorganized attachment style.
When a securely attached infant is distressed when its primary caregivers leaves, it is soothed by the return of the primary caregivers.
These infants think their caregivers will respond when they are in distress.
About 20% of American infants have an avoidant attachment style.
When their primary caregivers leaves the room, they are not concerned.
These infants think their caregivers won't respond when they're in distress.
Roughly 15% of American infants have an attachment style.
An infant will be distressed when its parent leaves the room.
An infant with a secure attachment style will not be soothed by the return of its primary caregivers.
It can ignore its caregivers attempts to calm it.
The caregivers of these infants are not sure if they will respond when they are in distress.
Less than 5% of American infants have a disorganized attachment style.
In the strange situation, an infant will show no pattern of responses when its parent leaves or returns.
Some psychologists believe that infants with disorganized attachment are confused about their caregivers, which may be an indication of abuse.
A child's attachment style may change over time.
Attachment styles are more prominent in some countries.
A secure attachment style is the most common in every country that has ever been studied.
In Japan, where mothers stay at home, children are more likely to have ambivalent attachment styles than they are to have avoidant attachment styles.
Attachment is an interaction between two people, while temperament describes an individual's pattern of emotional reactivity.
There are differences in biology that lead to temperament differences.
Between 10% and 15% of infants have limbic systems.
When shown a new toy or object, such individuals tend to cry and become distressed, grow into children who avoid new people and situations, and become shy and cautious adults.
The three main types of infant temperament are easy, difficult, and slow-to-warm.
According to research, temperament has an impact on attachment style.
It is possible that easy infants have a secure attachment style because they are easier to deal with.
Attachment theory focused on the attachment between an infant and its primary caregivers in the 1960s.
Attachment theory was applied to intimate relationships between adults in the late 1980s.
There were many similarities between adult and child relationships.
Adults want to be close to each other, feel comforted when their partners show them care, and experience distress when ignored.
Four attachment styles were proposed by Hazan and Shaver.
Attachment styles that were proposed between infants and primary caregivers are correlated with these attachment styles.
There is a single avoidant attachment style in children.
Adults who are secure tend to be able to form deep relationships.
They think they are capable of love.
Individuals with a secure attachment style are comfortable with their independence and do not fear being alone.
They tend to see themselves and their relationships in a positive light.
Adults with anxious-preoccupied Attachments tend to seek high levels of intimate relationships very quickly.
Adults with this attachment style worry that their affection for their partner is not reciprocated.
People with a low sense of self-worth tend to fear being alone.
Individuals who place a large value on independence and self-sufficiency are described in the dismissive-avoidant attachment style.
They don't engage in intimate situations.
Many people think these individuals are defensive and unwilling to discuss their feelings.
People with the fear-avoidant attachment style are often survivors of abuse.
They like close relationships, but also worry about the negative implications of a relationship.
They have difficulty with trust and dependence.
Diana Baumrind said that preschoolers exhibited different types of behavior that correlated with how their parents treated them.
There are four major parenting styles: authoritative, permissive, authoritarian, and neglectful.
There are two dimensions to parenting behavior.
The amount of control parents have over their children's behavior is called demandingness.
responsiveness refers to the degree that parents are sensitive to their children's emotional and developmental needs.
There are four parenting styles summarized in the table.
A style of parenting in which parents have high expectations for their children but are able to adjust them with understanding and support is calleditative parenting.
The most effective and beneficial style of parenting is this one.
The parents of these children are warm and responsive.
Children who are well-behaved and have high self-esteem are more likely to be raised by them.
Permissive parenting is a style of parenting in which parents are responsive but not demanding.
In order to avoid confrontation, these parents may establish inconsistent rules with their children.
They are warm and responsive, but they are easy to give in to their children's wishes.
Children raised by these parents tend to be impulsive and egocentric.
Authoritarian parenting describes parents who are cold and demanding.
Even when their children succeed, these parents tend to have very high expectations and fail to show positive reinforcement.
Children raised by authoritarian parents have low self-esteem, low academic performance, and poor social skills.
In neglectful parenting, parents are cold and unresponsive to their children.
Parents who neglect their children tend to be indifferent to how their children behave.
They raise children who are impulsive, depressed and have an increased incidence of suicide.
The two theories of cognitive development that you need to know for the AP Psychology exam are those developed by Swiss psychologist Jean Piaget and Russian psychologist Lev Vygotsky.
When he presented children within the same age group with challenging problems, he found that they tended to make the same mistakes.
The table below summarizes his conclusion that children move through four stages of cognitive development.
The sensorimotor stage lasts from birth until about two years old.
Children in this stage rely on their ability to sense and move in order to understand the world.
Young children see things, touch things, and put things in their mouths and develop theories about how the world works.
There are two separate processes to these schemata.
A novel situation is the basis for assimilation.
If a child learns that tugging her favorite toy can bring it closer, she can use this knowledge to bring other objects closer to her.
When presented with new information, children sometimes need to revise their schemata.
This process of revising is called accommodation.
Imagine what would happen if a child tugged on the tail of a cat.
The cat would run in the opposite direction rather than coming closer.
The child could learn that tugging objects will bring them closer, but that the same isn't always true with animated ones.
As children reach the end of the sensorimotor stage, they develop a capacity known as object permanence.
When objects are no longer visible, object permanence is understood.
A young boy has a toy hidden under a blanket.
The boy would not think to check under the blanket because he thought his toy had vanished.
He would most likely just pull the blanket back, knowing that his favorite toy was out of sight.
The preoperational stage is from 2 to 6 years old.
egocentrism is a self-centered perspective that arises from the failure to understand that the world appears differently to different people.
Imagine placing a teddy bear on a table in front of a four-year-old girl.
A boy sits on the opposite side of a table with a teddy bear.
The front of the teddy bear is what the girl will describe to you.
Since she doesn't know how the boy sees something different than she does, she will still describe the front of the bear.
Children begin to develop a theory of mind when they reach the end of the preoperational stage.
Human behavior is guided by mental representations of the world according to theory of mind.
In other words, not everyone sees what you see, and this gives rise to the idea that the world appears differently to different people.
Children can overcome egocentrism by developing a theory of mind.
The girl from the previous example would have understood that the boy across from her saw the back of the teddy bear, not the front of it.
Children in the preoperational stage don't understand how actions transform objects.
Children learn how operations transform objects as they transition to the concrete operational stage.
In one study, Piaget showed children a row of cups and asked them to place an egg in each cup.
The number of eggs remained the same after being placed in cups.
The eggs were removed from the cups and spread in a wider line than the cups.
Children in the preoperational stage wrongly reported that there were more eggs than cups, while children in the concrete operational stage did not.
The concrete operational children understood that quantity is a property that is not affected by spreading out objects, which simply alters the objects' appearance.
The cognitive milestone conserves quantities even when outward appearances change.
The formal operational stage is the final stage.
The stage begins at age 11 and lasts through adulthood.
This stage is when children gain a deeper understanding of their own and others' minds and begin to reason abstractly.
Despite the fact that the concepts of morality and freedom lack physical representations, older children can understand and apply them.
The ability to consider possibilities and counterfactual situations is gained by children during this stage.
Lev Vygotsky believed that Piaget's theory did not appreciate social and cultural influences on cognitive development.
According to Vygotsky, children's cognitive development depended on their interactions with other people as well as their cultural tools.
Vygotsky is best known for his work on the zone of proximal development.
All children have a range of skills they can do on their own, as well as a range of skills they are incapable of.
The zone of proximal development is between the two ranges and includes a set of skills that children can do with the assistance of a more knowledgeable person.
A MKO is someone who has a better understanding of a task than the learner.
Learners gain new abilities by working on skills within their ZPD with the assistance of an MKO, according to Vygotsky.
Children learn how to ride bikes with the assistance of an MKO who already knows how to ride one.
Young children in the sensorimotor and preoperational stages tend to be egocentric, considering the world only from their own perspective.
The study of moral development is about how this happens.
The three major stages of moral reasoning can be divided into two substages.
The table below summarizes these.
The theory was worked out by studying individual responses to moral dilemmas.
The most famous of these is the Heinz dilemma, in which a man is unable to afford a life-saving drug for his dying wife and must decide whether to steal the drug from the druggist who made it.
The type of reasoning they offered to classify their moral development would be used by Kohlberg to ask participants why the man should steal the drug.
The morality of an action is determined by the consequences for the actor.
Most young children occupy this stage.
If an action is punished or rewarded, it is immoral.
Older children and adults should move to the conventional stage of reasoning.
The morality of an action is judged by the extent to which it complies with social rules.
People in this stage believe that people should follow the law and follow their culture.
Some adults progressed to the post-conventional stage of moral reasoning, but not all.
The morality of an action is determined by a set of general principles that reflect core values, such as the promotion of liberty, the right to life, or the maximization of happiness.
An action that violates any of these principles is immoral.
In some cases, it's justified to break laws if they conflict with principles.
Some evidence suggests that the stages are not as simple as they were first thought.
A person might use pre-conventional reasoning in one situation and post-conventional reasoning in another.
The classification scheme shows a set of moral reasoning skills that can be acquired over time.
Carol Gilligan said that the theory was biased in favor of a masculine perspective of morality that prioritized rights and justice.
She said that the theory implied that boys and men were more morally advanced than girls and women.
Gilligan proposed an alternative theory known as the ethics of care, which emphasized values such as compassion and kindness over obligations.
The moral intuitionist perspective maintains that human ethical behavior is a product of our emotional responses, which evolved to promote our survival and reproduction as a highly social species.
Most ethical reasoning is used to justify our decisions after the fact according to moral intuitionists.
The trolley problem is considered the following scenario.
A runaway trolley is hurtling down a track towards five people, as you stand on a bridge.
You realize that you can save these people if you switch the trolley to a different track, but doing so will cause someone else to die.
If you were like most people, you would pull the lever and not push the man off the bridge.
There is no morally relevant difference between the two scenarios.
One person dies while five live.
You want to cause the death of one person to save the lives of five people.
The person whose death you cause is not different.
Moral intuitionists think that the discrepancy is the result of our revulsion at making physical contact to kill someone and our relative comfort with impersonally pulling a lever.
The development of sexuality, personality, and social skills is one of the theories covered in the chapter.
Sigmund Freud believes that a person's basic personality is formed in childhood.
These sensitive periods psychosexual stages focus on pleasures and behaviors associated with specific parts of the body.
The child's libido is fixated on the erotogenic zone in each stage.
The psychic energy of an individual's id was defined by Freud.
Freud used the term libido to encompass all drives an individual possesses, including those not traditionally considered sexual.
Problems and conflicts at any psychological stage will affect personality in adulthood according to Freud.
The conflict can be caused by either being deprived or overindulged.
A person's libido becomes arrested at a particular psychosexual stage when there is a conflict.
The table that follows summarizes the stages.
During the first year and a half, an infant occupies the oral stage, during which time she focuses on the pleasures and frustrations associated with the mouth, sucking, and being fed.
Children that fixate on this stage may have an impulse to have things in their mouths.
According to Freud, an adult with an oral fixation may develop personality quirks such as depression, lack of trust, and envy.
After the oral stage the child moves on to the anal stage, in which she experiences pleasures and frustration associated with the anus, retention and excretion of feces and urine, and toilet training.
According to Freud, toddlers who experience issues with toilet training may become adults who are "anal retentive" or controlling.
The child's experience is dominated by pleasures, conflicts, and frustrations associated with the genital region.
Freud claimed that a child in this stage could cope with incestuous feelings of love, hate, and jealousy.
Freud described a boy's experience in the phallic stage as an effort to resolve the Oedipus complex, a development in which a boy develops sexual feelings for his mother and jealousy of his father.
He will come to identify with his father in an effort to resolve the conflict.
Freud believed that fixation in this stage could lead to issues with intimate relationships later in life.
Men may be jealous, competitive, and authoritarian if they have a phallic fixation.
Carl Jung proposed the Electra complex, in which a girl develops sexual feelings for her father and identifies with her mother to resolve a conflict, because Freud did not develop a specific account of what happens to girls in the phallic stage.
Women fixated in the phallic stage would display flirtatiousness, seductiveness, and jealousy according to Jung.
The child does not experience a major conflict during the latency stage, which lasts until the beginning of puberty, and instead focuses on the development of creative, intellectual, athletic, and interpersonal skills.
Freud believed that development in this stage did not affect an individual's personality.
The final stage of psychosexual development occurs after puberty.
The individual develops a full adult personality with the capacity to work, love, and relate to others in the genital stage.
Freud suggested that people who arecumbered by unresolved conflicts from preceding stages may have difficulty reaching the genital stage of development.
He said that a person who reached this stage would become a well-adjusted adult.
Freud's psychosexual stages are popular in popular culture, but most contemporary psychologists don't take them seriously.
The stages are based on case studies, but Freud is notorious for not taking notes until after interviewing patients.
Freud's theory is only studied in psychology for its historical value because of the issues with data collection and generalizability.
Freud influenced the work of a German-American psychologist.
Each of the eight stages focused on a particular conflict.
Similar to Freud, Erikson believed that resolving each stage's conflict would lead to successful development of particular abilities, while failing to resolve a conflict could result in negative long-term consequences.
The table below summarizes the stages.
The world can be frightening when an infant is born.
Babies look to their primary caregivers for stability.
A sense of trust can be developed if the infant gets consistent and supportive care.
Hope is the virtue that arises from this stage, as the infant will feel confident that it can rely on others.
A lack of success in this stage can lead to significant distrust in relationships, which can lead to long-term difficulties with intimacy and security.
Between the ages of 18 months and 3 years, a child becomes more active and starts to explore the world around her.
She makes choices about what to wear, what toys to play with, what to eat, and learns new skills like tying her shoes.
The increase in decision making and skill acquisition can make a child feel independent.
If parents don't allow their children to explore during this time, they risk their children not developing a healthy independence.
If a child is critiqued too much in this stage, she can doubt her abilities later in life and avoid trying new things.
The virtue that comes from this stage is will, which allows the child to try new things.
Between the ages of 3 and 6 children begin attending preschool for the first time and meet a lot of new people.
Children in this age group often engage in pretend play with their peers, which helps them learn how to control their environment.
If children are successful in this stage, they will be able to lead others and make decisions.
If a child doesn't have positive social interactions with his parents or peers, he may start to feel guilty about being a nuisance to others.
The child may grow up having difficulties establishing relationships with others as a result of this guilt.
The virtue that comes from this stage is purpose.
Children between the ages of 6 and 12 are exposed to a variety of new tasks and rules as they enter primary school.
A child's peer group has a bigger influence on her life.
Children need to demonstrate certain competencies in order to get approval from their peers.
A girl may spend hours learning how to ride a bike in order to get approval from her peers and other people.
Success in this stage will make a child feel confident and proud of her accomplishments.
Failure in this stage can make you feel inferior.
The virtue of this stage is competence, which allows an individual to be proud of herself.
Between the ages of 12 and 18 is when this stage occurs.
Values and goals help adolescents find a sense of identity.
An adolescent will ask himself who he is and what roles he wants to play.
The questioning comes from the fact that adolescents go through a period of significant social, emotional, and physical changes.
They need to try on a lot of hats.
Adolescents are more likely to experience difficulty during this stage if they receive external or internal pressure to fulfill an identity that is not right for them.
fidelity is a commitment to your sense of self.
This stage takes place from 18 to 40 years old.
Young adults share themselves with others and develop long-term relationships with individuals who are not family members during this time.
People who are successful in this stage are able to have meaningful relationships with other people.
Family and friends can also be in these relationships.
People who are not successful in this stage are more likely to have issues with intimate relationships with others, which can lead to feelings of loneliness and frustration.
Love is the virtue of this stage.
During middle adulthood, from 40 to 65, people tend to stay in a career, have long-term relationships, and have families.
Adults in this stage want to give back to the community by raising children and being productive in their careers.
Success in this stage leads to the development of virtue of care, the tendency to act benevolently toward other people and society at large.
If an adult believes that he is not making significant contributions to society, there can be a feeling of stagnation.
Individuals tend to take on fewer responsibilities after the age of 65.
People look back over their lives and think about their accomplishments.
ego integrity is the development of an individual's pride in her accomplishments.
If an individual feels regret, shame, or guilt about her past, she will likely develop despair, hopelessness, and depression.
Wisdom is the virtue of this final stage.
Being intersex is a broad classification that describes anyone whose biological sex is not clearly male or female.
When individuals enter puberty, their differences in biological sex become more pronounced through the development of primary and secondary sex characteristics.
About 2 years before males do, females start puberty.
Girls who reach puberty earlier are more likely to experience a variety of negative consequences.
Some people expect mature girls to act like adults because they don't have as much time to learn how to cope with adolescence.
Girls who mature earlier tend to get more attention from older boys, which can lead to risky behaviors such as alcohol and drug use.
When compared to biological identity, gender is a more complex concept and refers to one's psychological identification as male, female, or neither.
The idea of gender expression refers to how someone expresses their gender identity through fashion, pronoun preference, and physical appearance.
People whose gender identity does not match their sex at birth are referred to as trans.
A gender role is a set of expectations about what is appropriate for a particular gender.
Female gender roles in some cultures may include nurturing, raising children, and communicating, while male gender roles may include providing for a family, suppressing emotional responses, and being competitive.
A child's understanding of gender roles affects how he or she interacts with peers.
Children gain an understanding of gender roles around the age of 4.
The way in which parents talk to their children about gender roles has an impact on how they understand gender.
Children who are raised to see gender roles as inflexible tend to conform to their own gender roles more than children who are raised to see gender roles as flexible.
Children with inflexible views of gender roles are more likely to expect their peers to do the same.
Carol Martin's study shows that cross-sex behavior is discouraged in both genders.
There are constraints on what a child can do based on what their peers think is acceptable.
Children prefer spending time with their peers of the same gender until they are 16 years old, which serves to reinforce gender roles.
Between ages 11 and 14 and between 18 and 21 is the period of adolescence, which lasts until the beginning of adulthood.
The period of development includes a lot of changes.
The average adolescent will gain 40 pounds and grow 10 inches over the course of 3 to 4 years.
At age 10, girls tend to hit their growth spurt and reach their maximum height.
Boys reach their maximum height around 17 years old.
The growth spurts mark the start of puberty, which is the set of bodily changes associated with sexual maturity.
The development of primary sex characteristics, which are bodily structures and processes directly involved with reproduction, and secondary sex characteristics, which are not directly involved with reproduction, are included in the changes.
adolescence is a time of transition between the ease of childhood and the serious responsibilities of adulthood.
Some theorists think adolescents are adults who act out to prove they are mature because they have been denied a place in society.
Teenagers may act out by having sex, consuming alcohol, or breaking the law.
Popular media often portrays adolescents as being moody, but that may not be accurate.
According to research, adolescents are comparable to children in terms of mood stability and that their changes in hormonal levels have a relatively small impact on their moods.
An infant's brain is bigger than it needs.
By the time an infant is 2 years old, she will have more than twice the number of connections found in a grown adult.
She experiences synaptic pruning when she is an individual, a process in which synapses that are not frequently used are targeted for elimination.
During adolescence, there is significant synaptic pruning in the prefrontal cortex.
The time that individuals enter the formal operational stage of cognitive development corresponds to this.
During puberty, adolescents begin to develop an interest in sex.
A survey done in 2000 shows that over 70% of American women and 70% of American men have sex before the age of 18.
The United States has one of the highest rates of teenage pregnancies in the industrialized world.
Adolescents spend a lot of time trying to figure out what they want.
Young children tend to believe what their parents tell them, but adolescents spend more time with peers and begin to question who they are as people, separate from who their parents are.
The difference between children and adolescents is that adolescents define themselves by their relationships with peers, while children define themselves by their relationships with their parents.
The major task of adolescence is the development of an independent adult identity according to a psychologist.
It can be difficult to develop an independent adult identity.
There are a variety of groups that adolescents can join.
The values, attitudes, and beliefs that adolescents develop can be influenced by peer groups.
If a teenage boy befriends a group with disdain for authority and hostility towards other peer groups, he will likely adopt those attitudes as well.
Parents struggle with newfound independence that adolescents seek out.
Relationships between parents and adolescents tend to involve more conflict.
Human beings tend to peak in their early 20s.
Slow and steady decline begins as the brain and body continue to age, which does not end until death.
It's not all bad news.
According to research, people over the age of 65 tend to be happier than they were before.
Human beings tend to experience changes in their bodies as they get older.
As fat increases, bones weaken, skin becomes less elastic, and brain cells die more quickly, hair starts to thin, muscle mass decreases, and skin becomes less elastic.
10 to 15 years after puberty is when some of the physical decline of aging starts.
Between the ages of 45 and 55, females tend to experience greater difficulties having children after age 32.
Men experience a decrease in fertility after the age of 40, though many men retain some fertility into old age.
The prefrontal cortex is more prone to decline after the age of 65.
The most notable cognitive decline occurs with tasks that require effort, initiative, or strategy, which is why the prefrontal cortex is responsible for controlled processing.
Older adults experience the greatest reduction to their working memory when compared to their longterm memory, episodic memory, and semantic memory.
Research shows that people are able to compensate for cognitive changes by using other cognitive abilities more skillfully.
Young adults tend to use their right and left prefrontal cortex when working with spatial and verbal information.
Older adults tend to use both right and left prefrontal cortices with either type of information.
Natural neurological decline can be overcome by more distributed activation.
One of the reasons grandma can't find her car keys is that her prefrontal cortex has deteriorated.
Young adults tend to focus on acquiring information that will be useful to them in the future, such as recalling where they last left their keys, while older adults tend to focus on information that brings emotional satisfaction.
People are happiest after age 65.
Older adults are less likely to be affected by negative information.
Older adults show more activity in the amygdala when looking at pleasant pictures, while younger adults show less activity when looking at unpleasant pictures.
Our social circles get smaller as we get older.
Older adults prefer to spend most of their time with family or close friends.
Older adults have the same number of emotionally close partners as younger adults, but they tend to have fewer acquaintances.
The list of contributors to developmental psychology can be found in the Rapid Review section.
If you want to practice for an exam on this topic, go to Rapid Review and Practice.