794 vIII. EMERGING  ISSuES AND  NEW  DIRECTIONS
Despite the promise and the potential 
importance, it is not clear whether inter -
ventions on personality are feasible. First, 
there are the ethical challenges to chang -
ing aspects of personality, as personality 
often gets equated with a person’s identity 
and individuality. Interventions would thus 
reduce the variability in personality, lead -
ing to reductions in individuality, echoing 
the dystopian world of Vonnegut’s novella 
Harrison Bergeron, in which the constitu -
tion outlaws individual differences, such as 
cognitive ability. Proponents for personality 
interventions could argue that interventions 
are usually targeted to single characteristics, 
thus mitigating Harrison Bergeron’s con -
cern. Anecdotally, people have fewer prob -
lems with intervening on cognitive ability 
(on which schooling presumably intervenes; 
Ritchie & Tucker-  Drob, 2018) and to a 
lesser extent self-  esteem (which was intro -
duced into select schools; see Baumeister, 
Campbell, Krueger, & Vohs, 2003; Robins, 
Trzesniewski, & Donellan, 2012), presum -
ably because the poles of these dimensions 
are almost universally regarded as positive. 
In contrast, the benefits of high levels of per -
sonality characteristics may not be so appar -
ent. Although being high in conscientious -
ness is associated with a number of positive 
outcomes, there are still downsides to the 
trait that may prove undesirable (Jackson & 
Hill, 2019). Many people will likely be left 
uncomfortable with someone dictating what 
pole of a characteristic is considered posi -
tive, especially given evidence that each side 
has both positive and negative characteris -
tics (Nettle, 2006).
The second barrier to feasible personal -
ity interventions is that processes underlying 
naturally occurring personality changes are 
mostly unknown. Despite a relative accep -
tance that experiences can shift personality, 
there are few life events that are consistently 
associated with changes in personality (e.g., 
Van Scheppingen et al., 2016). It is useful to 
note this lack of progress toward identifying 
major events that are responsible for changes 
in personality before attempting to intervene 
on personality, because the mechanisms re -
sponsible for change in passive longitudinal 
studies and interventions are likely shared.
There are at least four issues to con -
sider that complicate designing effective interventions. First, there are psychologi -
cal mechanisms that promote stability in 
self- concept, presumably leading to greater 
personality consistency (Roberts, Wood, & 
Caspi, 2008). A strictly environmental view 
on changing personality may not actively 
change one’s self-  concept. Second, each en -
vironment is perceived subjectively. In terms 
of changing personality, it will be difficult to 
create subjective equivalence from the same 
objective intervention. Third, as seen in de -
cades of work on interventions for cognitive 
ability, the extent to which an experience im -
pacts someone is likely to be domain specific 
(Hertzog et al., 2008). This domain speci -
ficity would suggest that narrow changes in 
behaviors, thoughts, or feelings due to an in -
tervention would not lead to broad person -
ality change (see Jackson & Hill, 2019). In 
other words, it is easier to change some nar -
row behaviors but more difficult to change 
the broad thoughts, feelings, and behaviors 
that comprise one’s personality. Finally, 
when discussing changes in personality, it is 
possible that both personality structure and 
change occurs idiographically, at the indi -
vidual level (Beck & Jackson, 2020). If true, 
then the mechanisms responsible for change 
are person specific, resulting in the need for 
personalized interventions to find effects.
Despite these roadblocks and an unclear 
road map of how to change personality, a 
number of existing interventions provide an 
indication of the features of an effective per -
sonality intervention. These studies mostly 
originate outside the field of personality 
and attempt to change consistent behaviors, 
thoughts, and/or feelings that could be con -
sidered “personality.” It is worth noting, 
however, that in most cases, changes in per -
sonality could be considered a side effect, 
separate from the original intent of the inter -
vention. Below we describe the evidence that 
various interventions have had on broad be -
haviors, thoughts, and feelings that, in turn, 
may help identify what an intervention for 
changing personality would look like.
Types of  Personality  Interventions
Parent and  School  Programs
Many high-  quality interventions occur in 
early childhood, predicated on the idea 