I've found the opposite. Introverts are happy to be by themselves not because they need to sort them selves out but because they are at peace with their own company. Extroverts on the other hand constantly seem to need to work something out about themselves or the world around them and can only do so by bouncing the ideas off others. Many times the other person isn't even necessary more than a prop. I've had many conversations with extroverts where all I've added was "aha" and "OK" for 30 minutes while they basically monologued, only to have the other person thank me for the insightful conversation and claiming I really helped them out.