I don't think anybody fully understand the risks of not learning. I read a study about a reduction in neuroplasticity in people who relied on a GPS to traverse their surroundings, like a weakening of the ability to learn. I wouldn't be that surprised if neuroplastic changes continued with the failure to learn spelling. Is spelling not just mapping words to their correct spellings in the brain?

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6020662/

Here's a study, there could be a lot more work done but I think it's interesting.

Have people thought of the implications of replacing more and more spatial logic centers of the brain with tools like Chat GPT? Fun stuff to think about! Maybe in the future people will be classified as "learned knowledge clasically" and "has chat gpt".

It was easy for them to ask about marijuana use, and they could have excluded them from the study. There are better studies that do take this into account like this one:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6636695/

This systematic review of studies highlights the problem https://pubmed.ncbi.nlm.nih.gov/36276349/

Conclusions: This review provides an update to the 2018 NASEM report on chronic health effects of e-cigarette use. While the number of studies has grown, the certainty of evidence remains very low largely because of cross-sectional designs and lack of reporting on exclusive e-cigarette exposure. There remains a need for higher quality intervention and prospective studies to assess causality, with a focus on exclusive e-cigarette use.

"The vaping patients were not asked whether they used devices that contained nicotine or THC, although nicotine is more common."

This is a bad study if they failed to control for THC vapes and nicotine e-cigarettes separately.

It is common knowledge that THC causes dry mouth, which increases the rate of tooth decay.