322 
For most individuals, young adulthood is 
an exciting time. It is a time of exploration 
and profound changes, some of which have 
lasting consequences for the remainder of 
their lives. Young adulthood—  perhaps more 
than any other stage in life—is also a time of 
personality change. The direction of change 
is generally positive. Most young adults in -
crease in traits that reflect greater social 
maturity, improved interpersonal function -
ing, and openness to experience (Bleidorn, 
2015; Bleidorn & Hopwood, 2019; Roberts 
& Nickel, Chapter 11, this volume). The 
pronounced changes in personality during 
young adulthood have led to a great deal of 
speculation about the conditions and causes 
of these changes. Why do personality traits 
change more in young adulthood than in 
any other period of life? Why do most young 
adults change in the direction of greater psy -
chological maturity, while some fail to con -
form to this trend?
While virtually all major theories of per -
sonality development emphasize the impor -
tance of genetic influences, they differ in the 
role given to environmental influences and 
life experiences. Current theories of person -
ality development stress the importance of 
age- graded life transitions, such as graduat -
ing from school, marrying, or becoming a parent, over and above genetic maturation 
processes (Bleidorn, Hopwood, & Lucas, 
2018; Denissen, Luhmann, Chung, & Blei -
dorn, 2019; Hutteman, Hennecke, Orth, 
Reitz, & Specht, 2014; Kandler, Bleidorn, 
Riemann, Angleitner, & Spinath, 2012; 
Roberts & Nickel, Chapter 11, this volume). 
These life transitions presumably impact 
personality, because they are often associ -
ated with shifts in social roles and relation -
ships. As such, these transitions could mod -
ify, interrupt, or redirect life trajectories by 
altering individuals’ feelings, thoughts, and 
behavior (Orth & Robins, 2014; Pickles 
& Rutter, 1991). For example, the birth of 
the first child is a life transition that often 
requires sudden and dramatic changes in 
individuals’ daily behavior, routines, and 
relationships, which, over time, may trans -
late into personality trait changes (Belsky 
& Rovine, 1990; Bleidorn et al., 2016; 
Jokela, Kivimäki, Elovainio, & Keltikangas- 
Järvinen, 2009; Van Scheppingen, Denissen, 
Chung, Tambs, & Bleidorn, 2018).
In this chapter, we review the current 
state of scientific evidence regarding the im -
pact of major life transitions on personal -
ity change in young adulthood. Our review 
focuses on the Big Five personality trait do -
mains of neuroticism, extraversion, open -CHAPTER 14
Personality and Life Transitions 
in Young  Adulthood
Wiebke Bleidorn  
Jaap J. A. Denissen