Children differ in the number of words they understand and produce when learning to speak. This can be partially explained by differences in their genes. In her thesis, Ellen Verhoef investigated genetic influences that play a role for vocabulary development during the first three years of life, and examined how they relate to later-life skills. In addition, she disentangled complex genetic links of neurodevelopmental disorders with cognition- and education-related related traits.
The results of Ellen’s research show that differences in vocabulary development during early-life are related to multiple, distinct genetic factors. Some of them, especially those related to early word understanding, also explain differences in later-life language, literacy and cognition. Genetic overlap with neurodevelopmental disorders is highly complex and genetic links between ADHD and reading skills partially arise due to shared genetic influences with educational attainment.