4 Elementary School–Aged Children 85they age from 5 to 11. Some of these changes were highly correlated with the
development of verbal skills and they are believed to indicate more complex
connections that permit higher cognitive skill development paving the way
for learning.
Lenroot and Giedd (2006) identified the prefrontal cortex as the site of
children’s growing ability to control impulses, make rational decisions, and
integrate the brain’s activities. These abilities are often called “executive func-
tions.” Philip Shaw (“Inside the brains of smart kids,” 2006) noted that the
thickness of the prefrontal cortex increases between the ages of 6 and 11, and
then starts to thin out again; the children with the biggest changes seem to be
the brightest. Research indicates that children who have experienced abuse/
neglect have a 17% smaller (by area) corpus callosum (the brain structure
that helps integrate both sides of the brain) than nonabused children (Teicher
et al., 2004). Those who have experienced PTSD as a result of maltreatment
also showed smaller intracranial and cerebral volumes (De Bellis et al., 1999).
Brain development and the ability to control impulses are critical to the
ability to learn, to interact appropriately in social settings, and to develop peer
relationships. When the biological substrate (the brain) is not developed, chil-
dren are at a great disadvantage. The typical school environment requires an
ability to remain seated, raise one’s hand before speaking, and generally to
think before acting. At age 5, these are very difficult tasks for a large percent-
age of children, but by the time children move into second or third grade,
they usually have mastered these skills, likely because brain development
has allowed them to develop. Yet, children who have experienced abuse and
neglect have structural and functional brain changes that may put them at
a disadvantage, likely as a function of their own parents often having been
neglected or abused and not being able to create an optimal environment for
them (DeGregorio, 2013).
Along with brain structure and function, cortisol (the body’s stress hor-
mone) and the way it is managed through the hypothalamic-pituitary-adrenal
axis (HPA) are known to be affected by chronic stress and trauma (Bevans,
Cerbone, & Overstreet, 2008). Research with parentally bereaved children
found that their cortisol response was blunted, leaving them at higher risk
for depression and other health and mental health problems in adulthood
(Kaplow et al., 2013).
Biological development also involves genomics. Genetics was once
understood as a set of DNA (viewed as nonchanging) that individuals either
got or did not get—like a gene for brown eyes. Understandings of epigenetics
and the ways genes are turned on or off via methylation due to environmen-
tal exposures are evolving quickly and taken together are called genomics.
Essex et al. (2013) found strong associations between adverse childhood
events (ACE) and methylation with epigenetic effects; in a prospective study,
they showed how maternal stress during infancy and paternal stress in the
preschool years yielded changes in the methylation patterns of children later
in life. Although epigenetics is still in its infancy and cannot indicate what
outcome these changes indicate, one can extrapolate that the neurobiological
changes and changes in the HPA complex for managing stress likely play roles.
Physical play, another aspect of children’s lives from ages 5 to 11 is impor-
tant for developing healthy bones and muscles, as well as imagination. Due to