BPB 217 Week 4: Heritability and Biological Basis of Intelligence

A set of vocabulary flashcards covering heritability, biological markers of intelligence, developmental theories, and medical conditions affecting cognitive function.

Heritability ($h^2$)

The proportion of observed differences in a trait among individuals in a population that is due to genetic variation.

Monozygotic (MZ) Twins

Identical twins who share $100\%$ of their DNA, used in behavioral genetics to study the role of genes in intelligence.

Dizygotic (DZ) Twins

Fraternal twins who share approximately $50\%$ of their DNA, similar to ordinary siblings.

Parieto-Frontal Integration Theory (P-FIT)

A neurological model proposed by Jung and Haier ($2007$) stating that intelligence depends on the efficient interaction of the parietal lobes, frontal lobes, and white matter pathways.

Neural Efficiency Hypothesis

Proposed by Richard Haier, this hypothesis suggests that high-IQ individuals show lower glucose metabolism during cognitive tasks, using less energy for better results.

Processing Speed

A biological correlate of intelligence ($r \approx 0.30 - 0.50$) reflecting the quality of basic neural transmission and myelination.

Dopamine

A neurotransmitter that regulates prefrontal cortex function, working memory, and executive control; dysregulation is associated with ADHD.

Acetylcholine

A neurotransmitter important for learning, memory formation, and attention that is reduced in Alzheimer’s disease.

Flynn Effect

The steady rise in average IQ scores observed throughout the $20\text{th}$ century, approximately $3$ IQ points per decade.

Active GxE Correlation

A gene-environment interaction where individuals with higher genetic potential seek out more stimulating environments.

Scarr-Rowe Interaction

The finding that heritability of intelligence is higher in affluent environments and lower in deprived environments, where poverty acts as a suppressor.

Fetal Alcohol Spectrum Disorder (FASD)

The most common non-genetic cause of intellectual disability, caused by prenatal alcohol exposure resulting in permanent brain damage.

Congenital Hypothyroidism

A condition that causes severe intellectual disability if untreated, but is reversible with early thyroid hormone replacement.

Lead Poisoning

Environmental toxin exposure where each $10\,\mu g/dL$ increase in blood lead is associated with a $1 - 5$ point IQ reduction.

Fragile X Syndrome

The most common inherited cause of intellectual disability, typically more severe in males.

Sensorimotor Stage

Piaget's stage ($0 - 2$ years) where intelligence is expressed through physical action and the development of object permanence.

Zone of Proximal Development (ZPD)

Vygotsky's concept of the gap between what a child can do alone and what they can achieve with guidance.

Scaffolding

The support provided by a more knowledgeable person to help a child accomplish tasks, which is gradually removed as competence grows.

Working Memory

The ability to hold and manipulate information in mind simultaneously; a strong predictor of academic achievement and IQ.

Fluid Intelligence (Gf)

The capacity to reason and solve novel problems without prior knowledge; it peaks in early adulthood ($\approx$ age $25$) and then declines.

Crystallised Intelligence (Gc)

Accumulated knowledge, vocabulary, and skills learned through experience that typically grows or remains stable through adulthood.

Cognitive Reserve

The brain's resilience to neurological damage, built through education, demanding occupations, and mental stimulation.

Intellectual Disability (ID)

A neurodevelopmental condition characterized by an IQ below $70$, limitations in adaptive behavior, and onset before age $18$.

Mild Intellectual Disability

A classification for individuals with an IQ range of $55 - 70$, comprising approximately $85\%$ of cases.