oic... you sounded quite certain of what you were saying, so I assumed you had some idea what you were talking about.
There's actually a long list of words that describe each of them.
D: dominant, driving, demanding, determined, decisive doer
I: inspirational, influencing, inducing, impressive, interactive, interesting, interested
S: supportive, submissive, stable, steady, sentimental, shy, status-quo, specialist
C: cautious, competent, calculating, concerned, careful, contemplative
Having pulled out the book again, it seems it's outgoing vs. reserved instead of extroverted vs. introverted.