HedonicEscalator
Of course that cuts both ways, since if it were a pure win to be protected from the sun, we would all be dark skinned.
Not necessarily.
We know that humans need sunlight for optimal Vitamin D production, so this does happen to be true. But your logic here doesn’t hold up. Synthesizing melanin is metabolically costly. Cave creatures, which have no use for pigmentation but also incur no obvious direct disadvantages from it, often evolve albinism because of the benefits of repurposing melanin precursors for other needs.
Humans aren’t cavefish, but the principle applies. If you don’t need melanin, making it is a waste of energy, and benefits from sunlight aren’t necessary to explain the evolutionary pressure against pigmentation.
Cohort studies claiming benefits from UV exposure are not credible. It is impossible to separate UV exposure from positive traits correlated with UV exposure, such as exercising or having a social life, and no, you can’t just control for it.
It is true that your risk of dying from melanoma is low, and not worth freaking out too much about.
You should do a blinded test of your sun exposure with identical placebo sunscreen to see if the UV exposure itself is necessary for positive effects on your mood, for science.
IQ is normalized to mean 100, standard deviation 15 from a sample population of test takers, usually matched by age. The mean is set to 100, by design.
Technically, since widely used norming populations are usually drawn from developed countries and exclude people with severe disabilities, the “actual” mean IQ, if you were to test everyone in the world, is lower than 100.
It’s not controversial. I don’t think anyone knowledgeable in oncology would dispute that sub-sunburn UV exposure significantly increases risk of skin cancer. My aim here was to explain why we can be confident of this belief in as straightforward of a way as I can.
I haven’t looked at your links in detail, but the first and second cover the same ground as the first and second points I made (observable DNA damage + cancer from indoor tanning). As for the third, I wanted to avoid resting any points solely on cohort studies because I didn’t want to get into too much of the controversy there. Though I ended up getting pulled into it on Reddit anyways.