chapter 8 psych - human development

Human Development

A field of psychology that examines age-related physical, cognitive, and socioemotional changes across the life span.

Physical Development

Involves maturation wherein the body follows a universal, biologically driven progression in a generally predictable pattern. Examples: puberty, vision loss.

Cognitive Development

Includes changes in memory, problem solving, decision making, language, and intelligence that tend to follow a universal course early in life and considerably vary with age. Examples: memory might become weaker or decision-making slower in old age.

Socioemotional Development

Refers to social behaviors, emotions, and changes experienced in relationships, feelings, and overall disposition. Examples: baby bonding with their caregiver, a teenager building friendships.

Biopsychosocial Perspective

Recognizes contributions and interplay of biological, psychological, and social forces shaping human development.

Biological Factors

Includes genes, brain activity, hormones that shape human development.

Psychological Factors

Includes learning, emotions, personality that shape human development.

Social Factors

Includes family, culture, media that shape human development.

Mental Health History

Prior anxiety or depression that can affect a mother's mental health after childbirth.

Support System

Partner, family, friends that can influence a mother's mental health.

Hormonal Shifts

Changes such as drop in estrogen & progesterone that can affect a new mother's mental health.

Nature and Nurture

Nature = biological forces; Nurture = environmental influences. Development needs both.

Continuity

Gradual, steady change in development. Examples: gaining weight, learning more vocabulary.

Stages

Sudden, dramatic change in development. Examples: thinking abstractly.

Key Takeaway: Nature and Nurture

It's not 'nature or nurture,' it's 'nature and nurture.' Human development is shaped by their constant interaction.

Key Takeaway: Stages and Continuity

Some changes are gradual, and others happen in stages.

Quantitative Change

Change in amount, such as gaining weight.

Qualitative Change

Change in kind or type, such as a child's understanding of justice compared to a teenager's.

Example of Nature

Genes guide when we walk, talk, or reach puberty.

Example of Nurture

Lead exposure can harm learning; practice improves skills.

Example of Support System

A mother feels isolated because her family lives far away and her partner isn't around often.

Example of Hormonal Shift

A new mother feels overwhelmed due to hormone changes and lack of sleep.

Stability

Traits stay consistent over time.

Change

Traits can shift with experience.

Cohort

Group born around the same time, shaped by shared historical/cultural experiences.

Cross-Sectional Method

Compares different age groups (cohorts) at one point in time.

Example of Cross-Sectional Method

Compare 2-, 3-, and 4-year-olds' vocabulary.

Limitations of Cross-Sectional Method

Cohort effects can be confused with age effects.

Strengths of Cross-Sectional Method

Quick, efficient, and cost-effective.

Longitudinal Method

Studies the same group (cohort) over time.

Example of Longitudinal Method

Testing 2-year-olds, then again at 3 and 4 to track vocabulary growth.

Limitations of Longitudinal Method

Time-consuming and expensive; participants may drop out.

Strengths of Longitudinal Method

Provides information about the stability and change in development.

Cross-Sequential Method

Combines cross-sectional and longitudinal methods.

Strengths of Cross-Sequential Method

Tracks individual changes with age and compares generational differences.

Limitations of Cross-Sequential Method

Complex and expensive; requires many participants.

Key Takeaway on Stability and Change

Some characteristics remain stable, while others evolve over time.

Nucleus

Control center of the cell; contains chromosomes

Chromosomes

Threadlike structures made of DNA; 46 total (23 from each parent)

DNA (Deoxyribonucleic Acid)

Stores and passes on genetic information

Genes

Segments of DNA that make proteins; like tiny instruction manuals that tell the body how to make proteins

Sex Chromosomes

23rd pair of chromosomes that determines biological sex

XX

Genetic configuration for female

XY

Genetic configuration for male

Differences of Sex Development (Intersex Traits)

Natural variations in chromosomal, hormonal, or anatomical sex affecting about 0.5-1.3% of the population

Androgen Insensitivity Syndrome (AIS)

Genetically male (XY) but body is partially/completely insensitive to male hormones

Turner Syndrome (XO)

Condition with only one X chromosome, resulting in short stature, underdeveloped ovaries, and infertility

Klinefelter Syndrome (XXY)

Condition where males have an extra X chromosome, leading to taller stature and breast development

Identical (monozygotic) twins

One egg + one sperm → splits into two zygotes; share 100% of genes

Fraternal (dizygotic) twins

Two eggs + two sperm → two separate zygotes; share ~50% of genes

Dominant gene

Gene that determines the trait when versions are different

Recessive gene

Gene that is masked by the dominant gene

Polygenic inheritance

Inheritance of traits influenced by multiple genes

Genotype

Your complete set of genes (from 23 pairs of chromosomes)

Phenotype

Observable traits resulting from the interaction of genotype and environment

Epigenetics

How environment affects gene expression (not DNA sequence)

Teratogens

Harmful agents that affect embryos or fetuses

Fetal Alcohol Syndrome (FAS)

Condition caused by alcohol exposure during pregnancy, leading to small head, low IQ, and facial abnormalities

Germinal Period

0-2 weeks of prenatal development characterized by rapid cell division

Embryonic Period

3-8 weeks of prenatal development where major organs and systems begin forming

Fetal Period

2 months to birth, marked by rapid growth and organ maturation

Critical Periods

Short, specific time windows (e.g., weeks 3-8 of pregnancy) during which teratogen exposure can cause permanent structural damage.

Sensitive Periods

Longer, more flexible timeframes (e.g., brain development throughout pregnancy) where teratogen exposure can impact function, with some recovery possible through intervention.

Newborn Vision

Vision is blurry at birth; best focus is at 8-10 inches (caregiver distance).

Newborn Hearing

Hearing is active before birth; babies recognize mother's voice shortly after birth.

Newborn Smell and Taste

Smell and taste are well-developed; infants detect mother's breast milk scent and prefer sweet tastes.

Newborn Touch and Pain

Touch and pain are present before birth; newborns feel pain similarly to adults.

Rooting Reflex

Turns head toward touch on cheek.

Sucking Reflex

Sucks when mouth area is touched.

Grasping Reflex

Grasps object placed in hand.

Babinski Reflex

Toes fan out when foot is stroked.

Stepping Reflex

Makes walking movements when feet touch surface.

Moro (Startle) Reflex

Arms and legs extend after sudden noise/movement.

Neurons at Birth

At birth, there are approximately 100 billion neurons.

Myelin Sheath

Helps babies gain motor control, such as being able to wave or walk as they grow.

Synaptic Pruning

Unused connections in the brain are eliminated while strong ones are strengthened, increasing efficiency.

Infant-Directed Speech (IDS)

High-pitched, singsong tone used by caregivers that captures infants' attention and boosts language learning.

Vocabulary Explosion

Occurs at approximately 2-3 years of age when children rapidly expand their vocabulary.

Critical Period for Language

Early time when language learning is easiest and most natural; after this, normal first language acquisition is very difficult.

Sensitive Period for Language

Time of high learning potential for language; learning after this is still possible but less efficient.

Genie's Case

An example of the importance of early language exposure; isolated from language from 20 months to age 13 and did not fully develop grammar.

Schema

Mental framework or collection of ideas used to understand the world

Cognitive equilibrium

Desire for mental balance and understanding

Disequilibrium

Confusion when new info doesn't fit old ideas

Assimilation

Fitting new info into existing schemas

Accommodation

Changing schemas to include new info

Sensorimotor Stage

Stage from birth to 2 years where infants learn by using senses and movements

Object permanence

Understanding objects/people exist even when out of sight

Preoperational Stage

Stage from ages 2-7 where children use language and imagination to explore the world

Egocentrism

Limited perspective where children see the world mostly from their own view

Theory of mind

Realization that others have thoughts and feelings

Concrete Operational Stage

Stage around age 7 where children begin thinking logically about concrete objects and situations

Conservation

Understanding that quantity stays the same despite changes in shape or appearance

Formal Operational Stage

Stage around age 11 and up where individuals think logically and systematically about abstract ideas

Scaffolding

Support given to children, gradually reduced as they become independent

Zone of Proximal Development (ZPD)

Tasks children can do alone plus those they can do with help

Temperament

Individual patterns of emotional reactions and behaviors

High-reactive infants

Infants who show strong distress to new sights, sounds, smells

Low-reactive infants

Infants who are calm and less upset by new experiences

Easy temperament

40% of infants; regular routines, happy, easily soothed, likely to succeed academically