Reading and writing are, at their core, cultural and social skills. For a child to obtain reading and writing skills, continuous practice for several years, as well as support and encouragement from parents and teachers, are usually required. At the same time, research has shown that there is a strong genetic background involved in variation and difficulties in terms of reading and writing skills. Some advances have also been made in the comprehension of the neurobiological background of reading and writing difficulties.
Most research on causes of dyslexia and other reading problems have been conducted on a cognitive analysis level. A number of scientific works have shown that one core problem of dyslexia lies in the person's phonology, i.e. a disorder in terms of comprehending and manipulating language sounds, which in turn might lead the connection between letters and their sounds to become unstable. Several significant works have shown that people with dyslexia can develop their reading if they are made to train their phonological functions.
Other researchers have focused on visuoperceptual difficulties as a cause of dyslexia. Such research has for example been able to establish that people with dyslexia often have a less developed visual sensitivity to movement, and that measuring this ability can provide an indication of a child's reading development. One can expect a strongly increased interest over the coming years in researching the role of visual factors in the development of dyslexia, as well as in how visual and phonological factors interact while the child is learning to read.
Children with specific comprehension problems rarely have any phonological problems. However, other aspects of spoken language – such as vocabulary and syntax – are often poorly developed. Other studies have shown that children with specific comprehension problems may have deficiencies in certain so called executive functions, particularly regarding verbal working memory and planning ability.