The Divine Plan for — Blushing?

Although darker-skinned people do it as well, blushing is very noticeable in people of European descent. Some blush easily and others may not ever. It is considered attractive, and women's makeup includes a blush tint. Fish, animals, and flowers may have reddish tinges that are called blush.

Charles Darwin did not appreciate the notion of his time: Blushing was designed by God to display human shame. (Mayhaps that is true, but this child is not convinced.) What is interesting is that apes and other animals do not do it.

blushing bromeliad
Blushing bromeliad, Flickr / Tanaka Juuyoh (CC BY 2.0), an article on the flower is here
Darwin's disciples try to evosplain blushing, but they cannot get around the fact that it does not contribute an "evolutionary advantage." And why is it confined to the face and neck? Interestingly, blushing seems to be caused by an adrenaline release because of an emotional trigger. (It just occurred to me that it would be interesting to see if there's a similar response to white people turning red with anger.) Also, someone blushing from embarrassment may prompt other people to trust them.
[Darwin] concluded blushing was a uniquely human characteristic that appeared to defy evolution for several reasons. These reasons include that no one had been able to explain why something like blushing, which most often does not help—and may even hurt—the blusher, would evolve. In contrast to most emotional responses, blushing is not a conscious behaviour. As Darwin acknowledged, we cannot cause a blush. Rather, it is produced by the autonomic nervous system, “which is completely beyond our control”.

I have no shame in telling you that the article is found at "Blushing—another evolutionary enigma."