It has a lot to do with commitment and prejudice. There is no evidence that some people are less capable at certain tasks. If you grew up in a place where your intuitive and natural skills bring bread to the table, you would find it pointless to sit around and solve puzzle and sequence manipulations. It's about the pressure there is to complete certain tasks in my opinion.

I recall how that Cambodia was somehow deficient in iodine in their diet and this was causing intellectual development problems that the international community were looking to assist with alleviating. However as with many things in Cambodia corruption interfered with the implementation.

This along with the fact that the Khmer Rouge killed a large number of intellectuals and I'd say to take this survey with a grain of iodized salt.


https://pubmed.ncbi.nlm.nih.gov/32835437/

Universal Salt Iodisation: Lessons learned from Cambodia for ensuring programme sustainability

"Abstract
Iodine deficiency is the leading cause of preventable intellectual disability in the world, but it has been successfully prevented in most countries through universal salt iodization (USI). In 2011, Cambodia appeared to be an example of this success story, but today, Cambodian women and children are once again iodine deficient. In 2011, Cambodia demonstrated high-household coverage of adequately iodized salt and had achieved virtual elimination of iodine deficiency in school-age children. However, this achievement was not sustained because the USI programme was dependent on external funding, and the national government and salt industries had not institutionalized their implementation responsibilities. Recent... "


https://www.google.com/amp/s/www.voanew ... 01896.html

" Laillou was stunned to find that 90 percent of coarse salt and 40-50 percent of fine salt was now not iodized. And all of it was labeled as iodized....

For example, Cambodia is investing a lot of money at the level of the Ministry of Education to improve the education of their children,” he said. “But having a lack of iodine in the brain, it decreases [their] IQ by 13 points...

A lack of enforcement has been part of the problem, but Keahak would not comment on the failure of government agencies to apply the current law. He did confirm that no one has been prosecuted for failing to add iodine or for failing to monitor the system....

Until then, the failure to police the country’s salt output will keep damaging lives in what experts say was an entirely avoidable public health issue.