Child Development: Research Methods & Prenatal Growth
Understanding Processes in Development
What is a Process?
A description of what change happens, along what timeline. Remember that constancy can be thought of as ‘the lack of change’.
Identifying Process Components
Can you identify the cause, mechanism, and outcome of a given process and explain your answer?
- Cause: The initial factor (e.g., teacher math anxiety).
- Mechanism: The apparatus, method, or tool – how do we get from cause to outcome?
- Outcome: The results, change, or lack of change (e.g., girls’ math achievement).
Developmental Research Methods
Longitudinal Research
Following the same individuals or groups over an extended period.
Why Repeated Measures?
Because the same measures are administered to participants multiple times.
Questions Answered by Longitudinal Research
Longitudinal research can address questions such as:
- How does learning over the school year relate to teachers’ anxiety levels?
- It helps to explain individual differences between people.
- It also helps to investigate constancy over time.
Cross-Sectional Research
Comparing individuals of different ages at a single point in time.
Microgenetic Research
Following the same individuals over a short period, with frequent measurements.
- Designed to “catch” the process as it unfolds.
Mastering 3D Shapes: The Process
What happens right before children master 3D shapes?
Insight or Gradual Performance Increase?
Do children “get it” all at once, like an insight, or does performance increase gradually?
Studies show no effects of gender or condition (e.g., photos vs. foam shapes), and no interactions involving those variables. A main effect of age indicates that performance improves with age; children seem to be doing quite well (everyone is far above chance). This approach can be thought of as zooming in on a small process.
Themes of Child Psychology
Nature vs. Nurture
- Nature: Refers to our biological endowment, especially the genes we receive from our parents.
- Nurture: Refers to the wide range of environments, both physical and social, that influence our development.
All human characteristics are created through the interaction of genes and environment. The most fundamental question in child development is how nature and nurture interact to shape the developmental process.
Continuity vs. Discontinuity
Some researchers view development as continuous, where changes with age occur gradually, in small increments, akin to a tree growing taller each year. Others see it as discontinuous, involving occasional large shifts and sudden, dramatic changes, such as the transition from caterpillar to cocoon to butterfly.
Key Stages of Prenatal Development
Understanding the basic stages of prenatal development:
- Conception: The union of an egg from the mother and a sperm from the father.
- Zygote: The fertilized egg, which undergoes rapid cell division.
- Ovum Period: Generally refers to the first two weeks, from conception to implantation.
- Implantation: The process by which the zygote attaches to the uterine wall.
- Embryo: The name given to the developing organism from the 3rd to the 8th week of prenatal development.
- Fetus: The developing organism from the 9th week until birth.
Summary of Prenatal Development Milestones
Embryo at 4 Weeks
- Four folds develop in the head region.
- Primitive heart begins beating and circulating blood.
- Arm and leg buds appear.
Fetus at 5½ to 8½ Weeks
- Differentiation begins in the nose, mouth, and palate.
- By 8½ weeks, these are separate structures.
- This is a critical time when cleft palate can occur.
Fetus at 9 Weeks
- Rapid brain growth.
- All internal organs are present.
- Sexual differentiation begins.
Fetus at 11 Weeks
- Heart achieves its basic structure.
- Spine and ribs are visible.
- Major divisions of the brain are forming.
Fetus at 16 Weeks
- Growth in the lower body accelerates.
- Movement increases, including breathing movements and some reflexes.
- External genitalia are developed.
Fetus at 18 Weeks
- A covering of fine hair (lanugo) and a greasy coating (vernix caseosa) protect the skin.
- Thumb-sucking is visible.
Fetus at 20 Weeks
- More time is spent with the head down.
- Components of facial expressions are present.
- Significant weight gain and increasingly cramped quarters in the amniotic sac.
Fetus at 28 Weeks
- Brain and lung development significantly increases survival rate.
- Eyes can experience REM movement.
- Neural activity is similar to that of a newborn.
- Weight has tripled (reflecting cephalocaudal development).