I was recently discussing ASD with an Indian medical doctor who has lived and worked in the US. He is (like myself) an old believer that AS is a sufficiently distinctive condition for the purpose of diagnosis and the provision of services. As he is a medical doctor he uses ICD rather than DSM for diagnoses.
He is intrigued at the (almost exponential?!) rise in the number of children with AS in India since the mid 1990s, and he thinks that it is far too great and too rapid to be explained by genetics alone, but is instead the result of changes in the upbringing and lifestyle of children. India is a country that has changed almost beyond recognition in the last 25 years. So has the lifestyle of children.
He does not believe that the rise in the number of children with AS is the result of greater awareness and diagnosis. Indian culture 25 years ago was one that favoured extroversion and a gregarious lifestyle, along with quite sophisticated unwritten rules and non-verbal communication, so that any kid with AS (diagnosed or undiagnosed) 25 years ago would have stood out like a sore thumb and looked upon as being weird. Around 25 years ago you would probably find no more than one or two 'weird kids' with AS in a medium sized town. Now it's not uncommon to find at least one 'weird kid' with AS in every class in every school.
Over in the US he is equally intrigued about why AS is very rare amongst African Americans although it is encountered amongst children from other non-white races. Again, he doesn't think there is a lack of diagnosis amongst African Americans, because like with Indians 25 years ago, African Americans have a culture where any kid with AS will stand out like a sore thumb and be looked upon as being weird. However, traditional or Kanner type autism with speech and language delay is probably just as common amongst African Americans as it is amongst white Americans. As a sideline, people from more recent immigrant groups in the US – such as Indian Subcontinent, Chinese, Middle Eastern, and even black Africans – often find African Americans, and their culture and lifestyle, bewildering. They also tend not to get on well with each other due to a clash of culture and aspirations
He is wondering whether the rarity of AS both in India 25 years ago and amongst African Americans today is a result of a laid back and gregarious lifestyle, where children are not pushed into academics and encouraged to socialise and play. Indian parents both in India and the US want clever children who go into technical and professional careers, so they push them hard with Academics. In contrast, African American parents tend to push their children with sports and music, and deter them from excelling in academic subjects. Even black African parents in the US tend to push their children down an academic or business pathway.
It is crushingly unfashionable to dare to think that ANY type of ASD is a result of parental upbringing, but from his observations both in India and the US he can't help wondering whether AS really is nurture rather than nature. Something else he has noticed is that the eldest boy in the family is more likely to have AS than any of his other siblings.