Not really. It's just stereotypes. In addition being quiet does not mean you are in deep thought, it might just mean you are socially awkward, which is usually the case. In fact you should stop confusing your social awkwardness for intelligence. read more
However, on the other end of the spectrum, I have encountered very smart people who are quiet, reserved and reflective. However, in general I think that people who are interested in expanding their knowledge and worldview tend to be good listeners and talk little in the presence of someone who will help them gain new understanding. read more
The people who are the most intelligent are actually the ones you'd least expect to be smart. They patiently wait for other people to say what they need to say. They choose to open their ears rather than their mouths. The quietest people are the smartest people; the ones who talk less have the most brainpower. Go figure. These are the introverts. read more