quiet-the-power-of-introverts-in-a-world-that-cant-stop-talking-susan-cain

engaged in higher-wattage activities
like organizing team-building workshops
or chairing meetings.
Eysenck also thought that the basis of
these differences might be found in a
brain structure called the ascending reticular
activating system (ARAS). The
ARAS is a part of the brain stem that
has connections leading up to the
cerebral cortex and other parts of the
brain. The brain has excitatory mechanisms
that cause us to feel awake, alert,
and energetic—“aroused,” in the parlance
of psychologists. It also has calming
mechanisms that do the opposite.
Eysenck speculated that the ARAS regulates
the balance between over- and
under-arousal by controlling the
amount of sensory stimulation that
flows into the brain; sometimes the
channels are wide open, so a lot of
stimulation can get in, and sometimes
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