Related Experiment Video
Updated: Jul 16, 2026

Lexical Decision Task for Studying Written Word Recognition in Adults with and without Dementia or Mild Cognitive Impairment
Published on: June 25, 2019
Genetic and environmental influences on word recognition and spelling deficits as a function of age
Angela Friend1, John C DeFries, Sally J Wadsworth
1Department of Psychology, 345 UCB, University of Colorado at Boulder, Boulder, CO 80309, USA. angela.friend@colorado.edu
Abstract:
Previous twin studies have suggested a possible developmental dissociation between genetic influences on word recognition and spelling deficits, wherein genetic influence declined across age for word recognition, and increased for spelling recognition. The present study included two measures of word recognition (timed, untimed) and two measures of spelling (recognition, production) in younger and older twins. The heritability estimates for the two word recognition measures were .65 (timed) and .64 (untimed) in the younger group and .65 and .58 respectively in the older group. For spelling, the corresponding estimates were .57 (recognition) and .51 (production) in the younger group and .65 and .67 in the older group. Although these age group differences were not significant, the pattern of decline in heritability across age for reading and increase for spelling conformed to that predicted by the developmental dissociation hypothesis. However, the tests for an interaction between genetic influences on word recognition and spelling deficits as a function of age were not significant.
Related Concept Videos
Language and Cognition
Alzheimer Disease l: Introduction
Biological Influences on Intelligence
Attention-Deficit/Hyperactivity Disorder
Diagnostic Criteria and Symptoms
To diagnose ADHD, symptoms must manifest before age 12 and be evident across multiple settings.
Human Genetics
The complex relationship between genetics and psychology is observable through common biological components such...
Language Development
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...

