These are the main findings of a new sub-study from the Norwegian Mother and Child Cohort Study (MoBa):
- first-born girls of mothers with the highest education had the highest level of comprehension at both 18 and 36 months
- first-born boys of mothers with the highest education showed the greatest increase in the level of language comprehension from 18 to 36 months
- having a mother with the highest education led to a greater increase in comprehension level during this period for boys than for girls
The study included 45 000 children born before February 2006. The questionnaires sent to participating families included standard questions about child development, communication with and without words, plus language comprehension. Comprehension was defined as the ability to understand communication both with and without words.
The difference between the sexes was striking: Boys of mothers with the highest education had lower comprehension than girls of mothers with the lowest education. Children of mothers with lower education had generally less developed language comprehension at 18 months, and the differences increased up to three years of age.
Level of education was more important than birth sequence among siblings. Children with one or more older siblings were slower in language development than the first child at 18 months of age, but the difference decreased slightly up to three years of age.
The article is part of a doctoral thesis from Imac Maria Zambrana at the Norwegian Institute of Public Health.
J Dev Behav Pediatr 2012: Impact of Gender, Maternal Education, and Birth Order on the Development of Language Comprehension: A Longitudinal Study from 18 to 36 Months of Age.
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