Advanced Developmental Psychology: Lifespan Trajectories
Dynamic Systems and Epigenetics
Probabilistic Epigenesis
Modern developmental psychology rejects genetic determinism in favor of probabilistic epigenesis. Development is viewed as a bidirectional interaction between genes, neural structures, behavior, and the environment (). Epigenetic mechanisms, such as DNA methylation and histone modification, alter gene expression without changing the underlying DNA sequence, often in response to environmental stressors.
Longitudinal Methodologies
To accurately model developmental trajectories and distinguish intra-individual change from inter-individual differences, researchers must employ longitudinal structural equation modeling, such as Latent Growth Curve Modeling (LGCM).
Developmental Research Designs
Cross-Sectional
- Compares different age groups at a single point in time.
- Vulnerable to cohort effects.
- Cannot track individual trajectories.
Longitudinal
- Follows the same individuals over multiple time points.
- Measures true developmental change.
- Vulnerable to attrition and practice effects.
Which biological mechanism is a primary focus of behavioral epigenetics because it typically represses gene transcription?
DNA methylation involves the addition of a methyl group to DNA (often at CpG sites), which generally condenses chromatin and represses the transcription of that gene.
Correct answer: DNA methylation
What hypothesis suggests that intrauterine environmental conditions, such as maternal malnutrition, permanently 'program' the fetus's metabolism, increasing the risk of adult chronic disease?
The Barker Hypothesis (or fetal origins of adult disease) posits that adverse conditions in the womb can lead to epigenetic adaptations that increase the risk of metabolic syndrome and cardiovascular disease later in life.
Correct answer: Barker Hypothesis
Neurogenesis in Adulthood
Contrary to early dogmas stating no new neurons are formed after birth, adult neurogenesis has been robustly demonstrated in the subgranular zone of the dentate gyrus (hippocampus) and the subventricular zone. This process is highly sensitive to environmental enrichment, exercise, and chronic stress.