THE BIOLOGICAL EMBEDDING OF EARLY EXPERIENCE AND
ITS EFFECTS ON HEALTH IN ADULTHOOD
Socioeconomic gradient in health status exists across disease processes and shows up even in
newly emergent disease.
Gradient appears to be an “emergent property” that results from the interaction between the
developmental status of people and the conditions they encounter over their life course.
Although, socioeconomic status in adulthoods leads to differentials in morbidity and
mortality through disease onset – childhood also plays an important role.
In the West, higher income, better education, and jobs with more status, prestige, and
decision latitude provide the most suitable niches for adult life.
o These individuals tend to enjoy the longest, healthiest lives.
However, in the process – the role of childhood is often ignored.
A LIFE COURSE PERSPECTIVE
It is not entirely clear as to how life course perspective explains the gradient.
There are 3 reasons as to why childhood needs to be considered when looking at adult health
1. Gradient replicates itself on new conditions, such as heart disease (during the mid-
century) and HIV (at the end of the century). It is not specific to any particular
2. The socioeconomic gradient in health status found in adult life is paralleled by
socioeconomic gradients in cognitive and behavioral development in early life.
In Canada and the United States, these gradients are consistent by
kindergarten age and are related to differential access to resources.
3. Longitudinal studies show that early child development and the socioeconomic status
during childhood is linked to adult health status.
Healthy child development involves encouragement of exploration; mentoring in basic skills;
celebration of developmental advances; guided rehearsal and extension of new skills; protection
from inappropriate disapproval, teasing, or punishment; and a rich and responsive language
Research shows that socioeconomic status during childhood affects adult health status in 3
i. Latent effects where early life environment affects adult health independent of
ii. Pathway effects where the early life environment sets individuals onto life
trajectories that in turn affect health status over time.
iii. Cumulative effects whereby the intensity and duration of exposure to unfavorable
environments adversely affects health status, according to a dose–response
According to the latency model, specific biological factors (e.g., low birth weight) or
developmental opportunities (e.g., adequate exposure to spoken language) at critical periods
in childhood have a lifelong impact on health and well-being, regardless of subsequent life
o Emotional control, peer social skills, language development, and the understanding
relative quantity all have critical periods in the first 5 years of human life.
o Biologically plausible model
o Research showed using Romanian orphans that spent over 8 months of their early
years of life in Romanian orphanages that putting adequately nourished children in
unstimulating emotional and intellectual environments can retard cognitive and
behavioral development in a manner that is not entirely reversible.
o ***The association between low birth weight and cardiovascular disease in adulthood
is evidence of a latent effect.
o Once the critical period is past, there is no way to gain those experiences or reverse
the damage – which is why enrichment programs are often confined to the early years
In practice, latent effects can be difficult to disentangle from pathway effects.
Pathways model acknowledges that differences in early life environment may direct
children onto different life courses. (e.g. stimulation, stability, and security in early childhood
affect a child’s cognitive readiness for schooling and receptive language)
o The prevalence of aggressive behavior in childhood does not peak in the teenage
years as is commonly thought, but rather by 24 months of age.
o The principal opportunity for socializing nonaggressive behavior falls between age 2-
5 – otherwise, one may be at an increased risk of lifetime aggression.
o Behavioral problems and failure in school lead to low levels of mental well-being in
o Also, the status of one’s parents helps to determine the community where one grows
up, which, by the early school years, starts to influence the child’s life chances
through the social networks, community values, and opportunities that present