Myth: Wearing hats causes baldness.
May 23rd 2017 by Tony Maleedy.
No it doesn’t. This is a myth started by the Victorians who probably wanted something to blame for baldness. Hats do not, under normal circumstances, cause baldness. The exception to this being traction alopecia (hair loss due to pulling) which can be caused by very tight fitting hats worn over a long period of time. But this hair loss usually occurs at the sides or the back of the head where the hat is rubbing, not the front and the top.
The science bit:
It is possible for some hats made with synthetic materials that don’t allow an escape of air and heat to cause or exacerbate some scalp disorders which can, in turn, lead to hair loss. But the chances of this occurring are very slim.