students over the nearly 3-month period. But this is a case in which averages
tell only part of the story. Clearly, the two students lead very different emo-
tional lives. Student A has highs and lows, but these typically aren ’t extreme.
We all know people like this; we call them steady and even-tempered. They
enjoy themselves but rarely become ecstatic. They get irritated but rarely
irate. Each of us also knows people like Student B. When they get happy,10 0 2 03 04 05 06 07 08 09 0–6–5–4–3–2–1123456
0Mood
PositiveStudent A
NegativeMood
Positive NegativeDay Number
10 0 2 03 04 05 06 07 08 09 0–6–5–4–3–2–1123456
0Student B
Day NumberFIGURE 8.3 Examples of Daily Mood Fluctuations in Two People
Source: From “The Stability of Mood Variability: A Spectral Analytic Approach to Daily Mood Assessments, ”
by R. J. Larsen, Journal of Personality and Social Psychology , 1987, 52, 1195 –1204. Copyright © 1987 by
the American Psychological Association.208 CHAPTER 8 The Trait Approach