AP Psychology - Unit 3.2 Physical Development Across the Lifespan

Prenatal Development

refers to all stages of growth and development that happen inside the womb from conception until birth.

the body and brain undergo rapid growth and formation

three distinct stages;

• germinal stage

• embryonic stage

• fetal stage

Germinal Stage

• conception - 2nd week

• zygote attaches to the uterine wall

Embryonic Stage

• 3rd - 8th week

• the heart begins beating

• limbs start to develop

Fetal Stage

• 9th week - birth

• embryo begins to look distinctively human

• organs and systems grow and mature

Teratogens

agents that can cause birth defects or developmental problems in an embryo or fetus

impact of these substances vary depending on;

• length of exposure

• the stage of pregnancy that the exposure occurred during

• genetic factors

• type of substance

slight consumption can affect the fetal brain

Maternal Illness

any disease and/or infection the mother endures during pregnancy

• puts the child at risk for health problems and psychiatric disorders

Genetic Mutations on Prenatal Development

• occur spontaneously when DNA is being replicated

• can be inherited

lead to various genetic disorders that can affect physical and cognitive development

Maternal Stress

stress hormones that flood the mother’s body can indicate a survival threat to the fetus

• causes early delivery

Environmental Factors on Prenatal Development

 any external elements that can potentially affect prenatal development

• air pollution

• water contamination

• radiation

• pesticides

influence the major physical and psychological milestones

Fetal Alcohol Syndrome (FAS)

• caused by the birth mother consuming large amounts of alcohol during pregnancy

• children with FAS experience physical and cognitive function deficits

Hormonal Factors on Prenatal Development

chemical messengers are responsible for regulating bodily functions, including aspects of fecal development

• brain growth/development

Atypical Brain Development

• caused by imbalances in hormones

• affects behavior and cognitive abilities

Infant Reflexes

involuntary movements that help with survival

• indicate healthy physical and psychological development

• present in newborns and infants until they are 4-6 months old

Palmar Grasp

• infant’s reflex to close their fingers around an object that is placed in their palm

Plantar Grasp

• infant’s reflex to curl their toes when the sole of their foot is stimulated by pressure

Babinski Reflex

• when the sole of an infant’s foot is stroked, their big toe will move upward, and their other toes will fan out

Rooting Reflex

• when something touches a baby’s cheek, it will move its head towards that direction, open its mouth, and await something to suck on

• helps with breastfeeding

Moro Reflex

also known as the startle reflex

causes a baby to throw its arms out and then pull them back in when startled

• demonstrates a basic protective response

Physical Development of an Infant

happens in the same order

• example: babies learn to roll over before they begin to sit up

the age at which an infant reaches each physical milestone can vary due to;

• genetic factors

• environmental factors

• cultural factors

Social Connection in Newborns

newborns have a natural preference for sights and sounds that promote social responsiveness

• critical for early bonding and communication

newborns spend more time looking at face-like images

• demonstrates an innate attraction to human faces

Maturation

the orderly sequence of biological growth

• enables an individual to reach their full potential physically, cognitively, and emotionally

Gross Motor Skills

involve large movements and large muscles

allow a child to navigate their environment

• example: crawling or walking

Fine Motor Skills

involves small movements and small muscles

critical for tasks such as;

• feeding

• playing

• drawing

Visual Cliff Experiment

provides insight into when an infant develops depth perception

babies would hesitate or refuse to crawl towards their parent due to the illusion of a drop off

• this indicated that the infant had the ability to perceive depth

Critical Period

• a crucial window of time where a particular skill must be acquired

• skills like language can not be developed after this frame of time

Imprinting

 an ability that newborn animals have that appears during critical periods of development

• newborn animals form a strong attachment to the first moving object they see (generally its mother)

Sensitive Period

• a time period where the brain is able to quickly learn a skill

• skills can still be learned after this frame of time, but it will be way more difficult

Adolescence

the transitional phase between childhood and adulthood

during this stage, individuals will experience;

• hormonal changes

• intense mood swings

• development of primary and secondary sex characteristics

• growth spurts

Puberty

the biological process during which children transition into adulthood

• the individual reaches sexual maturity, which allows them to reproduce

Primary Sex Characteristics

• traits that are developed during puberty that are directly related to the reproductive system and the ability to reproduce

Secondary Sex Characteristics

traits developed during puberty that are indirectly related to reproduction

• example: men developing broader shoulders

Menarche

first time a female menstruates

• example of a primary sex characteristic

Spermarche

first time a male ejaculates

• example of a primary sex characteristic

Growth Spurt

• a rapid increase in height or weight

“Teenage Brain”

the prefrontal cortex is still developing

• this causes adolescents’ rational judgement to lag behind their emotional and hormonal development

adolescent brain is a work in progress

Synaptic Pruning

the process by which unnecessary connections between neurons are eliminated in the brain

• increases brain efficiency

Emerging Adulthood

• 18 - mid 20s

• marked by exploration and self-discovery

Early Adulthood

• 20s - 30s

• building careers

• forming intimate relationships

• individual reaches their physical peak

Middle Adulthood

• 30s - 65 years old

• involving stability and personal growth

• experience a gradual physical decline

Late Adulthood

• 65 - death

• associated with reflection and retirement

• focused on maintaing health

• individuals experience a reduction in muscle mass and flexibility

• reaction time starts to slow

• decline in sensory abilities

Menopause

• occurs in middle adulthood

• marks the end of a women’s menstrual cycle and the ability to conceive