 793
Personality traits are prospectively associ -
ated with a number of important life out -
comes, at all ages of the lifespan, sometimes 
decades in advance (Roberts, Kuncel, Shin -
er, Caspi, & Goldberg, 2007). A common 
response to these associations is to ask why 
they occur, prompting a hunt for mecha -
nisms that relate personality with outcomes 
such as health, divorce, educational at -
tainment, and job success (e.g., Solomon 
& Jackson, 2014). An alternative response 
to the predictive validity of personality is 
ask whether one can modify personality in 
order to improve individual outcomes. At 
present, there is crosscutting, global inter -
est in changing personality (Bleidorn et al., 
2019). The sheer magnitude of the self-help 
literature, as well as self-  reported desires 
to change personality (Hudson & Roberts, 
2014), indicate that many people are un -
happy with their current personality. Fur -
thermore, the potential for impacting many 
life domains has generated public policy 
interests (e.g., as universal preschool) that 
hinge on the ability to cultivate personality 
(Heckman, 2006). Despite the interest and 
potential payoff of personality interven -
tions, little is known about what makes an 
effective personality intervention.Should We Intervene 
to Change Personality?
Personality traits have a number of charac -
teristics that make them appealing targets of 
intervention. First, personality traits are as -
sociated with life outcomes in almost all do -
mains, even after accounting for background 
characteristics. Many of these outcomes 
take years to accumulate (e.g., health), so 
an intervention that targets processes early 
in the causal chain, like personality, would 
be optimal (Chapman, Hampson, & Clar -
kin, 2014). Second, a considerable body of 
research has demonstrated that personality 
traits are open to change across the lifespan. 
These changes likely occur due to experi -
ences rather than to aging processes alone, 
implying that personality interventions are 
possible (Roberts & Jackson, 2008). Third, 
personality is relatively consistent across 
the lifespan, suggesting that if personality 
is modified through intervention, the ef -
fects of the intervention will be longer last -
ing. Unlike more ephemeral constructs, such 
as mood, and more stable constructs, such 
as fluid cognitive ability, personality repre -
sents a middle ground of being both open to 
change and relatively stable.CHAPTER 38
Personality Interventions
Joshua J. Jackson  
Emorie D. Beck  
Anissa Mike