"In social psychology, shyness (also called diffidence) is the feeling of apprehension, lack of comfort, or awkwardness experienced when a person is in proximity to, approaching, or being approached by other people, especially in new situations or with unfamiliar people."
The article goes on to assert that shyness may be genetic, environmental, and/or related to experiences of growing up (i.e., again, it's environmental). It might even be a symptom of mercury poisoning (though that's unlikely in today's world and was even unlikely for anyone but hat-makers in olden times).
The article goes on to make a lot of repetitious and sometimes absurd assertions about how children learn to become shy, how shyness is influenced by culture, and even how the length of the days during the mid-point of gestation of a child is correlated with the child's shyness.
As Madame L's readers can imagine, Madame L was delighted with that idea, which confirms her ideas about astrology and about 90 percent of social and psychological research (at least as it is reported and understood in the popular press).
Dear Reader, are you shy? And if you are, do you know why? Have you been told (and do you believe) that you would be happier if you were gregarious and outgoing? Do you feel your shyness has affected your life unfavorably? Were you somewhat shy as a child but less so now?
Madame L found out about the etymology of the word "shy" on Wiktionary: 'From Middle English shy (“shy”), from Old English sċēoh (“shy”), from Proto-Germanic *skiuhwaz (“shy, fearful”). Cognate with Dutch schuw (“shy”), German scheu (“shy”), Danish sky (“shy”).'
Madame L will soon be reviewing a book which deals comprehensively and humorously and intelligently with the issue of shyness or introversion: "Quiet: The Power of Introverts in a World That Can't Stop Talking," by Susan Cain. (Yes, as you guessed, the very shy and introverted Madame L is enjoying the book very much.)