The conclusions in this article are dubious. All of the mentioned studies are about sleeping at lower temperatures and getting better rest, not sleeping naked. The "builds confidence" point doesn't include any evidence linking sleeping naked to an increase in confidence.
I can't believe any reasonable person would believe this kind of defective reasoning. Let's analyse it one by one:
> Confidence doesn’t just feel good; it’s the pillar of success. It pushes you to try new things, take on challenges, and persevere in the face of adversity.
I guess most people would agree with these if we assume he refers to inner confidence, not something you show to others.
> A University of Melbourne study found that confident people earn higher wages and get promoted more often than their less confident counterparts.
Of course the study is not linked, but again, this is not surprising and in line with common sense.
> Sleeping naked makes you more comfortable in your own skin.
And now he makes this giant leap inserting his own opinion, right after he mentions the study, without providing a grain of evidence.
> As your comfort with your body increases, so does your self-esteem and confidence.
Now he is using modus ponens. The problem is, he never proved the antecedent is true.
This kind of cheap tricks is typical of snakeoil salesmen. For the sake of people who read only HN headers, I'd even go as far as to edit the title here to "There is no proof sleeping naked makes you healthier and wealthier" (or: "Benefits of sleeping in lower temperatures").
The main benefit as I see it, is that pyjamas/nightshirts/nighties/socks/etc get restricted by friction against the sheets and other bed coverings. Every time you move, you probably need to wake enough to overcome that friction.
I gradually progressed through my 20s and thirties trying to get more comfortable at night, mainly by removing tops or bottoms of pyjamas. Then I had a brief phase of using a night-shirt, but that was just as unsuccessful.
Finally, around the age of 40, I took the bold (at the time) step of sleeping naked. Much better, much more comfortable. I have slept like that for decades since.
This is classic example of modern advertising. The links in the article lead to the website selling products whose team member (and co-founder) is the author of the article. It doesn't mean the actual contents of the article is false, but I feel less inclined to believe a businessman than a scientist when it comes to scientific issues. Heck, even sleep scientists can be very wrong (see Walker vs Guzey, discussed several times on HN).