 38. Personality Interventions  795
that if existing habits and tendencies exist, 
they can more easily be overwritten due to 
the “newness” of a child’s personality rela -
tive to that of an adult. These interventions 
take advantage of the fact that a child’s life 
is almost completely dictated by his or her 
guardians, thus allowing for interventions 
that target multiple aspects of a child’s life, 
from the family environment to the school 
environment. In addition to being presumed 
to be more malleable, childhood interven -
tions are also sold as cost-  effective: Early 
intervention provides more long-term effects 
due to the cumulative nature of most life 
outcomes (Heckman, 2006).
Several series of studies have focused on 
improving childhood mental and physi -
cal health. For example, the Nurse–  Family 
Partnership program provides low-  income, 
first-time mothers with pre- and postnatal 
education and home visits from nurses until 
the child reaches 2 years of age. Follow-  ups 
indicate potential impact on personality 
in adolescence, with program participants 
being less likely to engage in risky smoking, 
alcohol, or sexual behavior and to have been 
arrested (Olds et al., 1998). Similarly, the 
Chicago Child–  Parent Centers (CPC) pro -
gram creates a stable environment so as to 
promote optimal academic and behavioral 
development (Reynolds, Temple, Robertson, 
& Mann, 2002) and is associated with bet -
ter graduation rates and reduced arrest rates 
(Reynolds, Ou, & Topitzes, 2004). Studies 
such as these indicate that early interventions 
can have later life influences, potentially via 
personality, but the mechanisms responsible 
could operate through pathways other than 
personality. The Carolina Abecedarian Proj -
ect (Campbell et al., 2014) found that the 
intervention effects are partially, but not 
entirely, due to socioeconomic status (SES), 
education, IQ (Conti, Heckman, & Pinto, 
2016), leaving the door open to changes in 
personality mediating some of these child -
hood intervention effects. However, few 
early-life interventions include measures of 
personality.
One of the only long-term intervention 
studies to include a measure of personality 
is the Perry Preschool Project (Heckman, 
Pinto & Savelyev, 2013). A broad behavioral 
measure assessed during adolescence sug -
gests that this intervention led to childhood differences in personality, which influenced 
later life health and labor-  market outcomes 
(Heckman, Pinto, & Savelyev, 2013). The 
Perry Preschool Project was based on a 
Vygotskian approach that utilized active 
participatory learning. The program em -
phasized organizational skills, such as the 
ability to plan and execute tasks, as well as 
social skills, such as conflict management 
and cooperation. Although this is a prom -
ising study that provides a framework for 
the early life interventions that influence 
later personality, the Perry Project is limited 
in generalizability by being a single, small 
sample study of a relatively disadvantaged 
population.
The Perry Project was a prototype version 
of what effective early interventions could 
be and, as such, has since been emulated. 
A great number of Head Start programs, 
for example, employ a modified version of 
the Perry curriculum (Head Start Impact 
Study, 2010). Like the Perry Project, Head 
Start also shows later life benefits that are 
not attributable to the effects of cognitive 
ability (Carneiro & Ginja, 2014; Deming, 
2009; Feller, Grindal, Miratrix, & Page, 
2016). However, a recent study found no 
personality differences during adolescence 
between those that were in Head Start ver -
sus a matched sample that either received a 
different type of daycare or no daycare at 
all (Jackson, Beck, & Weston, 2020). Alto -
gether, childhood programs appear to be ef -
fective later in life, there is limited evidence 
that their effectiveness is due to changes in 
personality.
Antisocial Behavior and  Juvenile 
Delinquent  Programs
Another common type of intervention is 
centered around antisocial behavior. Pre -
ventive awareness programs, such as Scared 
Straight, are based on the idea that youth 
can be deterred or scared away from deviant 
behavior by familiarizing them with the con -
sequences. In Scared Straight, children are 
taken to visit prisons to deter them from en -
gaging in misconduct. Such juvenile aware -
ness programs quickly gained popularity, 
despite evidence that they are largely ineffec -
tive. Indeed, a meta-  analysis of randomized 
clinical tests of juvenile awareness programs 