more likely to be introverts. Those in the noisy room said they preferred the
amount of noise and the opportunities for socializing. The others said theychose the quiet room to get away from these distractions.
These findings are entirely consistent with the theorists ’descriptions of
extraversion-introversion. Introverted students are more sensitive to stimula-tion. Thus an introvert in a noisy room is probably so disturbed by all the
activity that he or she will have a difficult time studying. On the other hand,
the understimulated extravert probably finds the quiet room boring. Unlessthe study material is particularly exciting, the extravert will probably take a
number of breaks, look around for distractors, and generally have a difficult
time keeping his or her mind on the task.
This difference in preferred stimulation level also is found in more con-
trolled laboratory experiments (Geen, 1983). For example, extraverts morequickly press a button to change slides on a visual learning task, presumablybecause they become bored more quickly with the pictures and designs (Brebner &
Cooper, 1978). One team of researchers found that extraverts, but not in-
troverts, showed a sudden drop in their ability to perform a listening exercisewhen the task was suddenly made less challenging by slowing down the pace
(Cox-Fuenzalida, Angie, Holloway, & Sohl, 2006). In another study, extraverts
and introverts worked on a word-memory task while listening to noise through
earphones (Geen, 1984). When given the opportunity, introverted participants
set their earphones at considerably lower levels than did extraverts. However,
some introverts in this study were forced to listen to loud noise and some extra-
verts were restricted to soft noise. Consistent with Eysenck ’s model, the intro-
verts did worse when exposed to higher levels of stimulation, whereas the
extraverts performed worse when listening to the softer noise.
This last finding helps to explain why some students can study only with
music or a TV blaring, whereas other students have to find a quiet library
room and then stuff pieces of foam into their ears to block out any remainingnoise. Too much stimulation makes it difficult to concentrate, and even extra-
verts can reach a point when they have to turn their radios down. But for in-
troverts this point comes much earlier. Of course, the other side of the coin isthat too little stimulation also interferes with performance. Whereas it may
take hours of solitude to bring an introvert to this point, a few minutes in
quiet isolation might be tough on a high extravert.
Extraversion and Happiness
Clearly, extraverts and introverts lead different lives. We are more apt to find
extraverts at parties, visiting friends, going places, and generally being active.Introverts are more likely to spend time alone, engaging in quiet, low-
stimulation tasks. Who do you suppose is happier? Not surprisingly, I usually
find introverts guess introverts are happier people, whereas extraverts can ’t
imagine how anyone could lead a life as boring as the introverted style.
Although introverts may have difficulty understanding this at first, re-
searchers find that on average extraverts report higher levels of happiness than
introverts (DeNeve, 1999; DeNeve & Cooper, 1998; Lucas & Baird, 2004;
Lucas, Le, Dyrenforth, 2008). Extraverts and introverts in one investigation262 CHAPTER 10 The Biological Approach