PSYCO105 Lecture Notes - Lecture 29: Umbilical Cord, Confounding, Prenatal Development
1 May 2018
School
Department
Course
Professor
Development over the Lifespan (Chapter 12)
What is developmental Psychology?
❏Study of age-related changes in behavioural and cognitive process.
Issues in Developmental Psychology
1. Nature versus Nurture → How much of psychological developments is from nature (genes) versus nurture
(upbringing).
a. Interested in what to extent these factors impact psychology because we know that they both affect
the development of psychology.
2. Critical and Sensitive Periods → Ease of learning is easiest at a young age.
a. Critical Period → Around the age of 5 years old.
3. Stability Versus Change → Behaviour of cognition increases over time.
4. Continuous versus Stage Changes → the transition from infancy to adulthood.
a. Continuous development → Gradual development
b. Discontinuous development → A leap in development as an infant ages.
Research Designs
❏Common Designs
1. Cross-Sectional Design → Different age groups compared at one time.
a. Example; Group A (20 yr old) versus Group B (50 yr old) versus Group C (80 yr old)
b. Issues arise due to varying environments (confounding variable) → 80 year olds have a
historically different environment when it comes to education, healthcare etc.
c. Benefits → Cheaper, one-shot method
d. Bad → Cohort effects, history differences, technology differences, attitude differences.
2. Longitudinal Design → The Sample participants are studies over time.
a. Example; Group A at age 20 → Group A at age 50 → Group A at age 80.
b. Issue; Time consuming (60 years) and costly. However, you can examine the differences
over their lifetime.
c. Benefits -> Controls for historic change
d. Bad → Drop-out and cost.
Compromise Design to accommodate weaknesses of two designs.
❏Third design gets around some of the weaknesses of the other two designs.
3. Sequential Design → Takes more than one group over time. This design helps with cohort
differences but they are more costly.
Physical Developments
❏Maturation → Programmed biological process that governs our growth, follows two principles.
1. Cephalocaudal Principle (from greek kephale [head] + cauda [tail]) → Child is disproportional at the
top to begin but as they age they begin to become more proportional as they age (from top to
bottom).
2. Proximodistal Principle → Development begins at the centre of the body (shoulders) and works
outwards to arms and fingers and legs and feet.
A) Prenatal Development → Three stages.
1. Germinal → first two weeks
2. Embryonic → 2-8 weeks
a. Placenta (link for food and protects against some harmful substances) and umbilical cord
(connects to fetus) develop
b. Head develops fastest.
3. Fetal → 9th week, Where 28 weeks is defined as the age of viability.
a. Rapid weight gain and detailing of body organs and systems.
❏Sex Determination → Genes stored in chromosomes; 46 total (23 pairs)
Document Summary
Study of age-related changes in behavioural and cognitive process. Issues in developmental psychology: nature versus nurture how much of psychological developments is from nature (genes) versus nurture (upbringing). a. Common designs: cross-sectional design different age groups compared at one time, example; group a (20 yr old) versus group b (50 yr old) versus group c (80 yr old) b. Longitudinal design the sample participants are studies over time: example; group a at age 20 group a at age 50 group a at age 80. b. However, you can examine the differences over their lifetime: benefits -> controls for historic change, bad drop-out and cost. Compromise design to accommodate weaknesses of two designs. Third design gets around some of the weaknesses of the other two designs. Sequential design takes more than one group over time. This design helps with cohort differences but they are more costly. Sex determination genes stored in chromosomes; 46 total (23 pairs)
