A significant interaction between childhood maltreatment and
low MAOA activity alleles has been found. This is associated with in-
creased risk for antisocial behavior and violence. Individuals with
high levels of MAOA expression did not show the same increase in
conduct disorders as did those with low MAOA activity in relation to
maltreatment in early childhood.
An important point that comes from this work is that it shows a
nongenotype mechanism for transmitting patterns of behavior for ge-
netically vulnerable animals to the next generation.In the case of the serotonin transporter gene, a female with the
short promoter gene structure who has suffered from poor early in-
fant development will have behavior problems, such as depression, as
a consequence of poor early development. She will then be at risk to
poorly bring up her offspring, who could have a similar gene struc-
ture. These offspring will likely suffer from the same behavioral prob-
lems as the mother.
Lifelong Effects of Experience-based Brain Development
Beyond the biology of early child and brain development, behavioral,
literacy, and population health research clearly shows that conditions
of early childhood affect and set trajectories for health, behavior, and
learning for children throughout life. The antecedents of adult health,
behavior, and literacy—among other qualities—lie in early childhood.
The evidence is substantial, as indicated below.
Early Child and Brain Development and Health
Conditions during pregnancy and early life influence the develop-
ment of the brain and biological pathways that set risks for coronary
heart disease, hypertension, type II diabetes, mental health problems,
and other conditions in adult life, such as disorders of the immune
system. The findings from a Swedish longitudinal study show that
children brought up in poor environments (with neglect and abuse)
during early child development have an increased risk in adult life for
poor health.
Scientific Underpinnings of the Importance of ECD in a Global World 57