Development
Developmental Psychology
- Interested in change, either how much or little change has occurred
- The study of how humans grow, develop, and change though the life span
- Development: the sequence of age-related changes that occur as a person progresses from
conception to birth
Issues In Developmental Psychology
- Special considerations:
• Post hoc fallacy – false assumption that because one event occurred before another
event, it must have caused that event
Causal relationships, ignores other possibilities for the relationship
• Children’s development influences their experiences, but their experiences are also
influenced by their development (bidirectional influences)
2 way street
- Nature versus nurture
- Continuous or stages
• Development can occur in stages or continuously. Ex: language is learnt in stages
- Stability of personal characteristics over time
• Stability indicates that it is genetically predetermined
Nature Vs. Nurture
- They interact!
- Gene-environment interaction – the impact of genes depends on the environment in
which the behavior develops
- Nature via nurture – genetic predispositions can drive us to select and create particular
environments
• This often appears to be a pure effect of nurture - Gene expression – some genes “turn on” only in response to specific environmental
events
• We analyze this through twin studies. Ex: if one twin is schizophrenic, then it is likely
that the other twin also has that gene, and we wonder what would cause the gene to
turn “on”, like drug use
Designs
- Temperament: refers to characteristic mood, activity level, and emotional reactivity
- Cross-sectional design: examine people of different ages at a single time point
• Measure different groups. Ex: for a span of 15 years, you want to measure the change
in self-esteem you would measure different age groups like 3-5 year olds, then 7-8…
to get your data
- Longitudinal design: track the development of the same group of people over time
• Could do over short or long periods of time, you would be following the same group
over the needed time length. But then you risk of getting people to drop out of the
study and then your sample size is not a good representation of a population, also this
cost a lot
- Able to control for cohort effects
• People dropping out either because of lack of continual interest or they die, leading to
a bad representation of a population in your sample group, this costs a lot, and is very
time consuming
Genes and chromosomes
- Genes: the biological blueprints that determine and direct the transmission of all
hereditary traits.
Stages of prenatal development
• Atotal of 40 weeks, but it’s really only 38 weeks, the first two weeks, you aren’t really
considered to be pregnant
- Prenatal period: extends from conception to birth, usually encompassing nine months of
pregnancy
- The germinal stage: first phase of prenatal development, encompassing the first 2 weeks
after conception • Period of the Zygote – first two weeks after conception, rapid cell division occurs
(Before the embryo implants itself onto the wall of the uterus)
Zygote: a one-celled organism formed by the union of a sperm and an egg
Placenta: structure that allows oxygen and nutrients to pass into the fetus from the
mother’s bloodstream, and bodily wastes to pass out to the mother
- The embryonic stage: second stage of prenatal development, lasting from 2 weeks until
the end of the 2 month
• Period of the Embryo – 3 week through 8 week, when the major systems, organs,
and structures of the body develop (The first 8 weeks consists of real fast
development)
- The fetal stage: third stage of prenatal development, lasting from two months through
birth
• Period of the Fetus – from 9 weeks to birth
- Age of variability: age at which a baby can survive in the event of a premature birth
• Between 22 and 26 weeks
Negative Influences on Prenatal Development
- Teratogens: Substances that can cross the placental barrier, which have a negative impact
on prenatal development, e.g., drugs
• Examples: drugs, alcohol, a maternal stress (stress hormones), anxiety, exposure to
chemicals, x-rays, and inadequate nutrition.
- Critical periods: Times in development when certain events may have lasting
consequences to the development of the fetus
• For the brain, psychological and physical periods; as well as human development
periods (after birth) Ex: attachment development critical period is between 12-24
months after birth, if this bond isn’t formed, then you will never be able to form this
bond ever again
• Exposure to teratogens during critical periods will affect physical development
- FetalAlcohol Syndrome: a collection of congenital (inborn) problems associated with
excessive alcohol use during pregnancy
• We don’t know how much or how little alcohol will cause FAS • Caused by drinking during pregnancy. The child is mentally retarded, has an
abnormally small head, wide-set eyes, and a short nose, and may have behavioral
abnormalities (e.g., hyperactivity)
Physical Development
- There are individual variation, physical development norms are averages, and it’s
perfectly normal to stray from the norm
- Infancy – sitting, standing, walking
• At around 12 months
- Adolescence – puberty: timing of puberty and: gender differences, culture, emotional
climate
• Timing of puberty Relates to social and emotional development
• Emotional climate Ex: a girl’s relationship with her father can predict her puberty. If
she has a bad relationship, she will menstruate sooner
- Middle age – menopause – both genders experience decline in hormones, males more
gradual and later
• Changes in old age: specifically cognitive changes with seniors. General intelligence
doesn’t really change, is fairly stable. Memory is greatly influenced on how active we
are cognitively and reaction time/speed of processing information declines with old
age
Motor Development KNOW ONLYTHESE, OTHERS IN THE TEXTBOOKARENT
IMPORTANT!!!
- Motor development: refers to the progression of muscular coordination required for
physical activities
- Cephalocaudal trend: head-to-foot direction of motor development
- Proximodistal trend: center-outward direction of motor development
- Maturation: development that reflects the gradual unfolding of one’s genetic blueprint
- Developmental norms: indicate the median age at which individuals display various
behaviors and abilities
- Reflexes – automatic motor behaviors, often present at birth • Sucking reflex
• Rooting reflex tap or stroke infant on the cheek it will open its mouth. Reflex will
disappear
- Motor Behaviors – self-initiated body movements
• Some kids don’t start walking till they’re 3 or older because they aren’t given the
opportunity to learn to walk. In some cultures, kids are carried for a long time
- Nature (pre-programmed) vs. Nurture accounts
Piaget’s Stages of Cognitive Development
- Cognitive development: transition in youngsters’patterns of thinking, including
reasoning, remembering, and problem solving
- Assimilation: interpreting new experiences in terms of existing mental structures without
changing them
- Accomodation: changing existing mental structures to explain new experiences
- Sensorimotor (0-2 years) – Infants gain an understanding of the world through their
senses and their motor activities
• Not much going on, very basic, schemas, problem solving consists of trial and error
• Object permanence: develops when a child recognizes that objects continue to exist
even when they are no longer visible
- Preoperational (2-7 years) – Children develop symbolic function and show tendenc
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