"Extraversion tends to be manifested in outgoing, talkative, energetic behavior, whereas introversion is manifested in more reserved, quiet, shy behavior." from Extraversion and Introversion
Making introvert software developers do agile development drives them insane because introverts
just do not want to work that way. The
cognitive dissonance is incredible. It
is not humane to ask introverted people to behave a certain way just so they
can meet some arbitrary concept of what doing good work means. And then all the best guys finally give up
and quit and the only ones left are the extroverts who can't code.
Here After the Gold Rush are some statistics about the percentage of introverts amongst software developers.