What evolutionary sense could it possibly make for humans to be bashful?

Robert Fulford in National Post:

Charles Darwin was confounded by an “odd state of mind” that he recognized in himself and many others.

Shyness.

Why did it exist? He could work out how lust, greed, love, etc. evolved as traits over many millennia. Each of them had a clear purpose in the creation and survival of humanity. But shyness? It was, so far as he could see, of no benefit to our species. And shyness could lead sometimes to blushing, another non-starter among human qualities. Darwin noted that it makes the blusher suffer and the beholder uncomfortable, “without being of the least service to either of them.”

Why?

The problem that Darwin never solved is the subject of a splendidly quirky book, Shrinking Violets: The Secret Life of Shyness (Yale University Press), by Joe Moran, who teaches cultural history in Liverpool. Moran searches tirelessly through history, literature, folklore and a little medicine without concluding why so many millions of us are shy. It remains as mysterious as it is pervasive. Some shy people suffer from feelings of inadequacy that they don’t care to acknowledge. Some may have secrets. When people say “I can’t stand cocktail parties,” that usually means they feel misplaced and self-conscious when talking to large groups of people whom they only half know. When they say “I have no small talk,” what they mean is that they’ve never mastered easygoing conversation. Moran doesn’t know why he’s often shy himself but realizes he’s a chronic case. Before he makes a phone call, he writes out what he wants to say. He keeps a notebook full of topics to raise when he finds himself at a loss for words, which apparently happens often. I’m also painfully shy on occasion and recognize Moran as a fellow sufferer, but I have never developed such an organized strategy.

From his perch in England, Moran observes that this is a national characteristic of the English.

More here.