 2. History, Measurement, and Conceptual Elaboration of the Big‑Five Trait Taxonomy  39
by the data. First, the ascent of the Big Five 
happened much more gradually than we 
had expected, and Cattell’s and Eysenck’s 
influence held steady much longer. Science 
moves slowly. As Figure 2.1 shows, it took 
until the early 2000s for the number of Big 
Five publications to finally overtake the two 
older models. Second, whereas references 
to the Cattell and Eysenck models have fi -
nally begun to decline in absolute numbers, 
their decline has been small compared to the 
amazing increase in research publications on 
the Big Five. For 2015–2019, the number of 
new Big Five publications exceeded 800 per 
year, compared with less than 200 for the 
two older models combined.
How can we explain this enormous 
growth in the number of publications on the Big Five? There are not enough person -
ality psychologists to publish that many 
papers per year. Our publication trend 
analysis shows that the Big Five have left 
the stuffy backrooms of full-time personal -
ity researchers and have made useful con -
tributions in a wide range of fields outside 
of psychology, such as comparative biol -
ogy and animal husbandry (e.g., Gosling & 
John, 1999; Gosling, Kwan, & John, 2003), 
education (e.g., Abrahams et al., 2019; John 
& De Fruyt, 2015), economics (see Heck -
man, Chapter 42, this volume), geography 
(see Rentfrow & Gosling, Chapter 40, this 
volume), music (e.g., Vella & Mills, 2017), 
and the wide range of now common internet 
behaviors, likes, and preferences (e.g., Nave 
et al., 2018).05001,0001,5002,0002,5003,0003,5004,000
1980–
19841985–
19891990–
19941995–
19992000–
20042005–
20092010–
20142015–
2019Num ber of publications
Public ation year
Cattell/Eyse nck Big Five/FFM
FIGURE 2.1. Number of publications related to either the Big Five personality traits or the influential 
models developed earlier by Cattell and Eysenck, identified in keyword searches of the PsycINFO da -
tabase. The numbers identified in the figure as Cattell/Eysenck  refer to the sum of all articles that used 
one of the measures developed by either Eysenck or Cattell, as indicated by the term “personality” plus 
either “EPI,” “EPQ,” “Eysenck Personality Inventory,” “Eysenck Personality Questionnaire,” “16PF,” 
or “16 Personality Factors”; those identified as Big Five/FFM  are the sum of all articles that used the 
term “personality” plus either “Big Five,” “Big 5,” “Five Factor Model,” “5 Factor Model,” or “FFM.”