Chapter 11: The Developing Mind: Life Span Development

Changes in the hippocampus and frontal lobes - third year of life - give children a boost in their abilities to form long-term memories

To form an autobiographical memory - children must have a sense of self

Babies as young as 18 months can recognize themselves in a mirror

The study of human development - considers changes in behaviour that correlate with growth or maturation

Different stages of life - three interwoven threads:

Epigenetic factors - diet, nurture, and stress

Younger children have more in common with each other since they lack many epigenetic changes

Two types of development

• Gradually and smoothly over time (continuity)

• Changes more abruptly from one stage to the next (discontinuity)

First two gestational weeks - developing organism is known as a zygote

Second gestational week - the zygote completes its journey through the mother's fallopian tube to the uterus - implants in the lining

During gestational weeks three through eight - we use the term embryo

After gestational week eight - we use the term fetus

First gestational week - the zygote differentiates into three germ layers: ectoderm, mesoderm, and endoderm

Ectoderm - develops into nerve tissue and skin

Mesoderm - gives rise to muscle and bone

Endoderm - source of the body's soft tissue - such as the organs of the digestive tract

Gestational week four - the central nervous system has differentiated into forebrain, midbrain, hindbrain, and spinal cord

Gestational week six - expression of a gene on the Y chromosome initiates the differentiation of sex - testes or ovaries

Gestational week seven - cells that will form the cerebral cortex move from the lining of the neural tube

Embryonic stage - nervous system, heart, stomach, liver, and other organs are formed during this period

Gestational month three - reproductive organs differentiate and new neurons are born in large numbers - start forming connections with one another

Gestational month six - Myelination of the nervous system begin

Gestational month seven - Most of the brain's cells have been formed

Most pregnancies last about 40 weeks - babies born between gestational weeks 37 and 42 are considered typical or term births

Babies born before 28 weeks of gestation - known as "micro preemies" and often do not survive

The more common genetic abnormalities seen in children are those that become more likely when their parents are older

Ex. Down syndrome, or trisomy 21 - results when the child receives a third full or partial copy of the 21st chromosome - usually because of faulty cell division

Placenta - organ attached to the wall of the mother's uterus that provides the fetus with nutrients and oxygen - protects fetus from exposure to toxins

Teratogen - Any agent that can produce harmful effects in the zygote, embryo, or fetus

Ex. antidepressant medications - has been linked to premature birth and autism spectrum disorder

Alcohol consumption by a pregnant woman can result in fetal alcohol spectrum disorder - comprised of three alcohol-related diagnoses:

• fetal alcohol syndrome (FAS)

• partial fetal alcohol syndrome (pFAS)

• alcohol-related neurodevelopmental disorder

FAS symptoms - nose and mouth abnormalities, and a small head circumference, reduced IQ, attention problems, and poor impulse control

A mother's use of alcohol, tobacco, marijuana, or cocaine during pregnancy significantly reduces the volume of grey matter of her child's brain

HIV - can be passed from mother to child during pregnancy, birth, or breastfeeding

Zika virus - produced small brains when prenatally exposed

Human development - is characterized by a longer period of dependency than in other primates

Newborns - birth to 28 days - spend 16/18 hours per day sleeping - most newborns also spend 2/3 hours crying - sometimes they cry for no reason

Rooting reflex - If an object is placed in the mouth, babies begin to suck reflexively

Grasping reflex - Reflexively grasp any object placed in the hand, voluntary grasping of objects

Stepping reflex - If parents hold newborns upright with their feet touching a surface they do a stepping motion

Physiological characteristics - having an XX or XY genotype - "sex"

Psychosocial aspects of the maleness-femaleness continuum - "gender"

Androgen insensitivity syndrome (AIS) - individual with male genetic sex (XY) cannot respond to circulating male hormones, leading to female external appearance

Congenital adrenal hyperplasia (CAH) - exposes the fetus to excess male hormones, might masculinize the external genitalia of genetic females

Habituation - the type of learning in which we reduce responding to repeated stimuli

Babies gaze longer at a new stimulus than at one they have seen previously - habitutation

Newborns are sensitive to smell - respond positively to sweet scents and their mothers scent

Infant's ability to hear - range of frequencies that normally occur in human speech which allows infants to learn language

Infants show a preference for looking at faces - further social behaviour and language learning

Young infants do not see detail at a distance as well as adults do - infants need more contrast than adults to see well

Latter months of pregnancy and first 18 months of life - the human brain shows rapid growth in grey matter or collections of neural cell bodies

Cells and connections that are not useful are systematically deleted in a process known as pruning

A burst of myelination occurs between the ages of 6 and 13 years in parts of the brain associated with language and spatial relations

Motor development occurs in 2 directions - head-to-toe direction and midline that goes outward

Gender identity - develops in response to both biological and environmental factors

Children begin to prefer sex-typed toys - between the ages of 12 and 18 months

CAH girls - show much greater interest than typically developing girls do in masculine toys

By 3 years old - children begin using gender labels consistently for themselves - this isn’t always the gender they identify with

Piaget's theory - cognitive abilities develop through regular stages

Two types of adjustments can be made to a schema

• Assimilation - no changes to the existing schema are required to add the new instance

• Accommodation - the schema must be adapted to fit the new information

The Sensorimotor Stage (0 - 2) - sensations immediately evoke motor responses for infants

Primary circular reactions (I to 4 months of age) - are actions that involve the infants' own body

Secondary circular reactions (4 to 8 months of age) - involve objects other than one's own body

Tertiary secondary reactions - which begin around the infant's first birthday, involve trial-and-error experimentation

The Preoperational Stage (2 - 6) - children are still incapable of engaging in internal mental operations or manipulations

• Younger children believe what they see is real such as movies and superheros

The Concrete Operational Stage (6 - 12) - problems of conservation are easily solved and thinking becomes more logical

The Formal Operational Stage (above 12) - ability to handle abstract concepts

Contemporary developmental psychologists argue that some aspects of Piaget's view of cognitive development need updating - didn’t care about external factors

Lev Vygotsky - stressed the role of culture and cultural differences in the development of the child

Language was a particularly important aspect of cognitive development for Vygotsky

Zone of proximal development - ideal conditions for learning - when a child is faced with a task that they can accomplish with the assistance of more knowledgeable people

Scaffolding - involves the parent or teacher being responsive to the needs of the child and providing guidance that matches the learner's needs

By the time children enter elementary school - performance on tasks requires attention that reaches adult levels

Significant changes in memory abilities after age 2 - due to maturation of brain structures

Amygdala & hippocampus mature early (6 months) - Changes in frontal lobe & hippocampus (age 3)

First autobiographical memories - occur around age 3

Young children understand objects earlier than - Piaget suggested, even with little experience

Egocentrism - Young children struggle with understanding others' viewpoints

Theory of Mind (TOM) - Recognizing that others have different beliefs, desires, and intentions

Premack's argument - TOM evolved from abilities seen in apes

False belief task - ("Sally-Anne") used to test TOM in 3-4 year olds

TOM deficits - linked to Autism Spectrum Disorder (ASD)

Mary Rothbart (2007) - divided temperament into three categories:

Temperament - shapes how children interact with their environment and elicit responses from caregivers

Harry Harlow (1958) - Studied rhesus monkeys - Contact comfort is critical for strong attachment

John Bowlby - Evolutionary perspective on infant-mother attachment - Young birds form immediate attachments - human infants bond more gradually.

Secure Attachment - Child is distressed when the mother leaves but easily comforted when she returns

Anxious-Avoidant - No distress when mother leaves, accepts comfort from stranger, avoids mother upon return

Anxious-Resistant - Always uneasy, highly distressed when mother leaves - alternates between clingy and rejecting upon return

Disorganized Attachment - Confused, contradictory behaviors (ex. approaching mother while walking backward)

Responsive parents - Teach children the world is predictable & safe - Children feel secure exploring

Unresponsive/inconsistent parents - Teach children the world is unpredictable - Children stay close, hesitant to explore

Parenting Styles - defined by parental support and behavioral regulation

Parental support → Empathy & recognizing the child's perspective

Behavioral regulation → Supervision, discipline, & clear expectations

Authoritative Parenting (High support + High regulation) - parents are consistent, firm, warm, & reasonable - encourage feedback but maintain clear authority - ideal

Authoritarian Parenting (Low Support, High Regulation) - prepares children for societal authority figures - more likely to use harsh punishments - can lead to rebellion

Indulgent Parenting (High Support, Low Regulation) - warm & loving but avoids enforcing rules - relies on teachers, neighbors, & law enforcement to set boundaries

Lower monitoring - Higher antisocial behavior in children

Puberty - hormonal surge - maturity of reproductive organs and secondary sex characteristics

Puberty in males - Muscle growth, genital maturity, facial hair, deeper voice (larynx growth)

Puberty in females - Breast growth, genital and uterine maturity, fat redistribution

Gender Identity - Personal sense of being male or female

Sex-Role Behavior - Traditionally masculine or feminine behaviors

Sexual Orientation - Stable attraction pattern (separate from gender identity & sex-role behavior)

Androgen Insensitivity Syndrome (AIS): Genetic males (XY) develop a female gender identity & sex-role behaviors

Congenital Adrenal Hyperplasia (CAH): Higher prenatal male hormones in girls - Higher rates of bisexual & lesbian orientation

Gray matter growth peaks at 11–12 years - thins during teen years

Excessive gray matter loss - Linked to early-onset schizophrenia (4x more frontal lobe loss)

Myelination of frontal lobes - continues into 23–30 years

Teens react to pleasure more strongly than adults - make worse choices for immediate rewards

Kohlberg - To assess changes in moral reasoning - gave people ethical dilemas and asked for reasoning participants gave

Kohlberg identified three major stages in moral reasoning

Erikson’s Psychosocial Theory - developed a life-span model of psychosocial development (stages from infancy to old age)

Erikson - contributed to the understanding of self

Despite stereotypes of miserable parents - most report higher happiness than nonparents

Marital satisfaction - drops after childbirth but rebounds as children gain independence

Evolutionary theory suggests grandmothers caring for grandchildren allowed parents to focus on other survival tasks

Menopause - Typically complete by early 50s (but fertility declines much earlier)

Common menopause symptoms: Irregular menstrual cycles, hot flashes, night sweats, headaches, joint pain, mood swings, sleep disturbances

Hormone treatments used cautiously due to risks (stroke, heart attack, breast cancer, dementia)

Men experience gradual reproductive changes throughout life - sperm quantity decreases - men in their 80s remain half as fertile as men at 25 - testosterone levels remain stable