 12. Personality Development in Middle Childhood  291
may arise in part because adults are typical -
ly the reporters of children’s traits, and they 
may not be able to distinguish children’s 
internal experiences of emotional volatility 
(neuroticism) from their external expres -
sions of anger and hostility (low agreeable -
ness). It is also important to note that the 
neuroticism trait does not replicate as clearly 
across cultures in childhood as other traits 
do (Tackett et al., 2012).
Conscientiousness  in childhood includes 
children’s impulse control, planning, high 
standards, perseverance at tasks, depend -
ability, attention, carefulness in work, and 
orderliness. As children move from middle 
childhood to later adolescence, conscien -
tiousness increasingly involves descrip -
tors that index principled behavior toward 
others, acceptance of responsibility, and 
dependability (Soto & John, 2014). Con -
scientiousness is more strongly related to 
agreeableness in childhood than in adult -
hood, suggesting the presence of an over -
arching self-  regulatory trait (Soto & Tack -
ett, 2015). Interestingly, conscientiousness 
in childhood is often associated with the 
intellect component of openness—  a link 
that does not occur in adulthood (Soto & 
Tackett, 2015) and that may result from the 
slow development of the prefrontal cortex 
in childhood and its potential influence on 
both traits (Shiner & De Young, 2013).
Agreeableness  is an especially broad trait 
in childhood. Children’s agreeableness in -
cludes their considerateness, kindness, co -
operativeness, compliance, concern about 
others, and generosity on the high end, and 
manipulativeness, aggression, bossiness and 
social dominance, anger, self-  centeredness, 
and stubbornness at the low end. All of 
these tendencies relate to how well children 
can regulate themselves in order to maintain 
positive relationships with both peers and 
adults; descriptors of agreeableness toward 
adults (e.g., compliance, obedience) are sa -
lient in child measures in a way that is large -
ly absent in adult measures of agreeableness. 
Childhood measures of agreeableness in -
clude strikingly large numbers of descriptors 
for the low end of the trait (De Pauw, 2017; 
Tackett et al., 2012), and this is true across 
cultures, perhaps because disagreeable chil -
dren pose so many challenges for adults. As 
noted previously, childhood agreeableness has stronger associations with low neuroti -
cism and high conscientiousness in child -
hood than in adulthood.
Openness/intellect  has proved to be the 
most challenging trait to define in child -
hood. Children who are high on this trait are 
quick to learn, knowledgeable, perceptive, 
imaginative, curious, and original. A recent 
study found a moderate correlation ( r = .41) 
between openness at age 10 and at age 30 
in a sample of American participants when 
childhood openness included items assessing 
children’s positive, energetic, enthusiastic in -
volvement in intellectual and academic work 
and in extracurricular activities, as well as 
the more typical descriptors for openness 
(e.g., creativity, curiosity, quickness to learn) 
(Shiner, Allen, & Masten, 2017). As noted 
previously, middle childhood is the period in 
which children in many cultures begin for -
mal school and engage in more extracurricu -
lar activities and hobbies, so openness may 
manifest itself during this period of life in 
children’s positive, enthusiastic engagement 
with academic and nonacademic tasks. In -
terestingly, there is evidence that the intel -
lect aspect of openness (e.g., good thinking, 
quickness to learn, good memory) emerges 
as a distinct factor in parent ratings across 
multiple cultures already by the age of 3 
(Tackett et al., 2012).
Finally, as noted, there is growing evi -
dence that activity  is a developmentally dis -
tinctive aspect of personality structure by 
at least preschool age (Shiner & De Young, 
2013; Soto & John, 2014). Activity level 
is an important trait in most temperament 
models (Shiner & De Young, 2013), but it 
has typically been neglected in personality 
models. Activity includes, not surprisingly, 
children’s tendency to be physically active 
and energetic; depending on the assessment 
measure, it may include youths’ assertive 
engagement and pleasure in striving to do 
things well (e.g., Soto & John, 2014)—or, 
instead, their tendencies toward impul -
sivity and sensation seeking (De Pauw et 
al., 2009). Activity may change as a com -
ponent of personality over time, shifting 
from reflecting primarily motor activity 
to reflecting achievement motivation and 
competitiveness, then eventually becoming 
a component of extraversion and conscien -
tiousness (Soto & John, 2014).