Can an extrovert learn to behave like an introvert?

Can a person who’s naturally outgoing learn to quiet down and focus?

In this recent discussion we saw some agreement on the idea that an introverted person can learn to act in a more extroverted manner, even if not actually becoming an extrovert.

An even more interesting question, it seems to me, is whether a person who sits at the “extrovert” end of the continuum can voluntarily take on more typically introverted behaviors:
•  enjoying solitude
•  remaining quiet and reserved when with others
•  avoiding risks
•  sustaining concentration on a project or activity for prolonged periods
•  being more intrinsically than extrinsically motivated
•  thinking first and speaking or acting second

Recent findings have pointed to a number of strengths found among introverts and some advantages that they have in areas of both personal and public achievement. If an extrovert wanted to acquire those advantages, would it be possible?