Genetic influence on language delay in two-year-old children
P S Dale1, E Simonoff, D V Bishop
1Department of Psychology, University of Washington, Seattle 98195, USA.
Nature Neuroscience
|April 9, 1999
Summary
Genetic factors significantly influence early language delay, distinguishing it as a unique disorder. Environmental influences are less impactful in delayed language development compared to the general population.
Area of Science:
- Developmental psychology
- Behavioral genetics
- Pediatric language disorders
Background:
- Most childhood language difficulties stem from genetic factors impacting brain development, not acquired lesions or environmental issues.
- The specific genetic and environmental influences on early language delay require further investigation.
Purpose of the Study:
- To conduct the first twin study on language delay.
- To determine if genetic and environmental factors differ between children with language delay and those in the normal range.
Main Methods:
- Assessed vocabulary at age two in over 3000 twin pairs.
- Utilized model-fitting analyses to estimate heritability and shared environmental influences.
Main Results:
- Heritability for the lowest 5% of language-delayed subjects was 73%, significantly higher than the 25% for the entire sample.
- Shared environmental influence was 18% for the delayed group, compared to 69% for the general sample.
Conclusions:
- Early language delay appears to be a distinct disorder with strong genetic underpinnings.
- Genetic factors play a more dominant role in language delay than shared environmental factors.
Related Concept Videos
01:11Genetic Lingo
Overview
01:28Human Genetics
Human genetics provides a profound framework for understanding the interplay between genetic predispositions and human psychology. At the heart of this discipline lies the study of how genes influence physical traits, behaviors, and susceptibility to diseases. Each person carries a unique genetic code that subtly or significantly shapes their psychological and behavioral landscape.
The complex relationship between genetics and psychology is observable through common biological components such...
The complex relationship between genetics and psychology is observable through common biological components such...
01:20Gene-Environment Interactions
Gene expression is a dynamic process that is significantly influenced by environmental factors. This interaction underlies the complex nature of biological development and the phenotypic differences observed among individuals, even among those with identical genetic makeups. Factors such as radiation, temperature, behavior, nutrition, and stress play pivotal roles in determining how genes are expressed. The concept of the reaction range is central to understanding this interaction. It posits...
01:22Language Development
Children master language quickly and with relative ease, supported by both biological predisposition and reinforcement. B. F. Skinner (1957) proposed that language is learned through reinforcement, while Noam Chomsky (1965) argued that language acquisition mechanisms are biologically determined.
The critical period for language acquisition suggests that the ability to acquire language is at its peak early in life. As people age, this proficiency decreases. Language development begins very...
The critical period for language acquisition suggests that the ability to acquire language is at its peak early in life. As people age, this proficiency decreases. Language development begins very...
01:27Language and Cognition
Language serves as a bridge between ideas and communication, influencing how individuals perceive and interact with the world. Psychologists have long debated whether language shapes thought or vice versa. This discussion gained grip with Edward Sapir and Benjamin Lee Whorf in the 1940s, who proposed that language determines thought, a concept known as linguistic determinism. They suggested that the vocabulary and structure of a language influence how its speakers think and perceive reality.
01:30Biological Influences on Intelligence
Intelligence is often thought to be linked to brain size, but the relationship is more complex than that. While brain size does correlate modestly with some abilities, like verbal skills, the connection is weaker for others, such as spatial reasoning. Other factors, like brain structure, also play crucial roles. For instance, despite Einstein's smaller-than-average brain, his parietal cortex, which is involved in spatial reasoning, was 15% wider, suggesting that neural density might matter more...