Important to remember that reading is a cultural phenomena. Not all cultures developed reading in the same way which raises issues concerning the next cognitive disorder. Chatterjee presented a case where an subject learned to read a second language in adolescence to the point where the second language dominated while the primary language regressed! (Something that does not normally happen where a dominant language is learned early, second languages are harder at this time.)
The difference revolved around the way different languages are acquired (grapheme or phoneme) which influence abilities to obtain the language particularly English, since the language has so many irregular words, require whole word exception.
This example lead to a discussion of developmental dyslexia which inhabits 5% population of school age children. SES is not thought to be causally related but does require both the need to combine eye and ear (rapid auditory processing and lexical command) and . However, biological indicators of the problem might include the magnocellular decrease (neurons involved fast switching) and abnormal cortical folding.
[Unfortunately the lack of etiology with dyslexia has prompted quick fix responses (computer programs) which actually are not as important than more difficult, highly related work with a tutor.]
What was overlooked in the illustration presented was that the adolescent could not read irregular words (English) where the adolescent could read Spanish which has all regular words. The desire to speak the second language did include adolescent behavior but the etiology was primarily around dyslexic ability to read another language at a level that was greater than anticipated (the subject could read Dantes in Spanish!).