Developmental disabilities (DDs) are common: about 1 in 6 children in the U.S. had a DD in 2006–2008.- The prevalence of any DD in 1997–2008 was 13.87%
- Prevalence of learning disabilities was 7.66%
- Males had twice the prevalence of any DD than females and more specifically had higher prevalence of ADHD, autism, learning disabilities, stuttering/stammering and other DDs;
- http://www.cdc.gov/ncbddd/developmentaldisabilities/features/birthdefects-dd-keyfindings.html
- Researchers do not know exactly what causes learning disabilities, but they appear to be related to differences in brain structure. These differences are present from birth and often are inherited. To improve understanding of learning disabilities, researchers at the NICHD and elsewhere are studying areas of the brain and how they function. Scientists have found that learning disabilities are related to areas of the brain that deal with language and have used imaging studies to show that the brain of a dyslexic person develops and functions differently from a typical brain.
- https://www.nichd.nih.gov/health/topics/learning/conditioninfo/pages/causes.aspx
- http://www.cdc.gov/ncbddd/developmentaldisabilities/features/birthdefects-dd-keyfindings.html