 35
Personality psychology is the science of indi -
viduality, and one tasks for our field is to de -
vise a conceptual language, or taxonomy, to 
describe individuality and specify how one 
individual differs from another. Consider 
the following description of one individual:
Thirty-  one-year-old Robert often feels rest -
less. He has problems sitting at a desk for 
more than a few minutes, cannot get orga -
nized, loses his keys and wallet, and forgets 
about his plans for the evening. He fails to 
achieve up to his potential at work. Dur -
ing conversations, his mind wanders and 
he interrupts others, blurting out what he 
is thinking without considering the conse-
quences. He gets into arguments. His mood 
swings and periodic outbursts make life dif -
ficult for those around him. Now his mar -
riage is in trouble.
How should we summarize Robert’s be -
havior, experience, and cognitions? What 
constructs should we use?
Personality psychologists in the 1980s 
offered many answers to these fundamen -
tal questions, and most of these answers 
were remarkably different from each other. “Surely, this young man has problems with 
ego undercontrol, and he certainly lacks 
ego resilience,” would be the likely analysis 
from Jack Block at the University of Califor -
nia, Berkeley; Block would use his Califor -
nia Q-sort (Block & Block, 1980) to assess 
Robert’s personality. In contrast, Harrison 
Gough (also at Berkeley) would use his Cali -
fornia Psychological Inventory (CPI; Gough, 
1987) to diagnose Robert with deficits in so -
cialization, self-  control, and responsibility, 
as well as low capacity for status and well-
being. And Ravenna Helson (also at Berke -
ley) would have administered Robert the four 
scales from the Myers–  Briggs Type Indicator 
(MBTI; Myers & McCaulley, 1985), which 
measures extraversion, feeling, judging, and 
intuition. Finally, Robert Hogan had gradu -
ated from Berkeley just a few years earlier, 
but he did not appreciate any of these three 
approaches; thus, he proceeded to develop 
his own, naming it the Hogan Personality 
Inventory (HPI; Hogan, 1986; Hogan & 
Hogan, 2007). In short, personality trait re -
search was organized into schools that often 
did not get along that well. Table 2.1 shows 
some of the schools that were most popular 
at the time and their favorite measures.CHAPTER 2
History, Measurement, and Conceptual 
Elaboration of  the Big‑Five Trait Taxonomy
The Paradigm Matures
Oliver P. John