1. Listen for sheer volume of words. How many words does this person use to convey his or her ideas? Introverts use far fewer words in a day than do extraverts of the same gender, and will say nothing if someone else has already conveyed the message. The prize for fewest words of all goes to the introverted male and the prize for the most words, embarrassingly, goes to yours truly, the female extravert.
2. Listen for content. How much personal information does this person share? Do you know much about his or her life? Does he or she share personal anecdotes with many people or just one or two? Introverts share little personal information until they already know a lot about you, and often not even then.
3. If you have access to this person's office or cube, take a look. The office of the introvert reveals little. A family photo, displayed where it can't easily be seen from the guest chairs, and perhaps some awards for successful projects. If the introvert has any say in the office layout, there will likely be a physical barrier (sometimes a very large one) between his or her chair and any guest chairs, such as a large table or long, rectangular desk that doesn't lend itself to sitting side-by-side.
4. Observe patterns of access. How easy is it to reach this person? Is his or her cell phone listed on the company directory? Does he or she have a private cell phone that only family and close friends can call (not that you would know - ha ha)? Does he or she have a Facebook page, and how well populated is it? Does his or her email signature include contact information or other information, such as favorite quotes? Extraverts put a lot of information out there. Introverts maintain more privacy on many fronts.
5. Watch for signals at the end of a meeting, particularly a long one. Does this person appear to be more tired or wired? Extraverts get energy from others, whether we want it or not, so at the end of a long meeting, the extravert will appear to be both tired and wired, even a little bit hyper-active at times. Introverts get energy from their inner world, so at the end of a full-day meeting, you won't see any hopping about. In fact, you probably won't see them at all, since they raced for the door at the first opportunity.
