Early development: Chances and Risks
Lecture 1: course introduction, biology, introduction and prep
assignment
Focus of this course
Socio-emotional development of children
During the first 1000 days: the period spanning roughly between
conception and one’s second birthday
Development proceeds at a breathtaking pace
How we view the role of nature versus nurture (environment) during
this developmental period changed over the years
It’s all nurture
Watson’s ideas are an example of behaviourism: the environment is
the supreme force in child development.
Nowadays: we more and more try to understand how the
environment impacts the expression of our biology
Environment influences expression of our biology
Bee example
Example 2: sleep trainings are examples of behaviourism: the
environment (i.e. parental behaviour) is the supreme force in child
development
Range of reaction: biology gives a range of developmental
possibilities
But also: biology shapes the environment:
E.g.: child with Down syndrome or child with difficult temperament
,Nature AND Nurture
The question is not whether biological OR environmental factors are
more important
But how the expression of our biology is shaped by the environment
we meet (programming: adapting to the environment you ewill likely
meet)
This notion is central to this course, because development will
never be as susceptible to the environment as during the first
1000 days!
Critical and sensitive period
Environment will have more or less influence depending on the
developmental period:
o Critical period: environment only has an impact during a
particular window, effects are irreversible
E.g. when a kitten does not open its eyes for the first
weeks in their lives, they will not be able to see even
after they open them
o Sensitive period: environment shapes a given trait or
behaviour to a larger extent than in other periods or stages
Early development as sensitive period
Developmental plasticity: capacity to adapt to different
envirronments
Adapting to the environment makes infants both versatile and
vulnerable
The first 1000 DAYS of life therefore contains:
Risks with lifelong consequences for health and wellbeing
Chances to ‘get things right’ and to boost childrens’ development
Developmental Origins of Health and Disease (DOHaD) hypothesiss
The DOHaD hypothesis or Barker hypothesis: exposure to certain
environmental influences during critical or sensitive periods of
, development may have significant consequences on an individual’s
short and long-term health (basically the same as the 1000 years)
The earlier the better
The study gene-environment contributions to individual differences”
Adoption studies: compare characteristics of adopted children with
those of both their adoptive and biological parents
Twin studies: compare the similarities between identical and
fraternal twins reared together or apart
True or false??? Identical twins have identical genes. So, if reared
apart any similarities they have must be due to shared genes, not
shared environment it is often overlooked that identical twins
already shared the womb (prenatal environments)
How much of this environment they share depends on chorionic
arrangements
Chorionic arrangements
Dichorionic twins (1/3): separate placentas and separate fetal
circulations. Can be identical or fraternal twins (doctors like this one
the best)
Monochorionic twins (2/3): one placenta and one fetal circulation.
Can only be identical twins. Brings more risks of e.g. one baby being
smaller due to getting less nutrition
Greater concordance for MC identical twins than for DC identical
twins on:
o IQ scores
o Personality scores
o Schizophrenia
o Physiological measures
But even identical twins that:
o Shared the same placenta,
, o Shared the same circulation,
o And shared the same environment
Can be very different
Conjoined twins
Abby and Brittany Hensel
Each has a heart, stomach, spine, lungs, and spinal cord
Each twin feels and controls 1 arm and 1 leg
They can eat and write separately and simultaneously
Activities such as running, swimming, hair-brushing, playing piano or
volleyball, riding a bicycle requires coordination
Two driver’s licences, one is married
We are totally different persons
Differences e.g. due to self-organisation in the brain; connections
that are made in each brain
Summary:
Our biology and the environment interact, shaping our development
The first 1000 days play an important role in development
Many twin studies have underestimated the influence of prenatal
environment
More about the prenatal environment: next week!
Lecture 2: Prenatal development
Prenatal development
Sensitive period: window for the environment to shape fetal
development (chances & risks)
Teratogens: agent that cause deviations during prenatal
development (teratology or developmental toxicity)
Can cause structural malformations, but also manifestations such as
growth retardation and delays in mental development
Thalidomide
Anti-emetic drug, first used as tranquiliser, but soon also to treat
morning sickness
Virtually impossible to give rats a lethal dose
>10.000 children born with severe malformations to the limbs
(phocomelia): around 40% of them died around birth
Lecture 1: course introduction, biology, introduction and prep
assignment
Focus of this course
Socio-emotional development of children
During the first 1000 days: the period spanning roughly between
conception and one’s second birthday
Development proceeds at a breathtaking pace
How we view the role of nature versus nurture (environment) during
this developmental period changed over the years
It’s all nurture
Watson’s ideas are an example of behaviourism: the environment is
the supreme force in child development.
Nowadays: we more and more try to understand how the
environment impacts the expression of our biology
Environment influences expression of our biology
Bee example
Example 2: sleep trainings are examples of behaviourism: the
environment (i.e. parental behaviour) is the supreme force in child
development
Range of reaction: biology gives a range of developmental
possibilities
But also: biology shapes the environment:
E.g.: child with Down syndrome or child with difficult temperament
,Nature AND Nurture
The question is not whether biological OR environmental factors are
more important
But how the expression of our biology is shaped by the environment
we meet (programming: adapting to the environment you ewill likely
meet)
This notion is central to this course, because development will
never be as susceptible to the environment as during the first
1000 days!
Critical and sensitive period
Environment will have more or less influence depending on the
developmental period:
o Critical period: environment only has an impact during a
particular window, effects are irreversible
E.g. when a kitten does not open its eyes for the first
weeks in their lives, they will not be able to see even
after they open them
o Sensitive period: environment shapes a given trait or
behaviour to a larger extent than in other periods or stages
Early development as sensitive period
Developmental plasticity: capacity to adapt to different
envirronments
Adapting to the environment makes infants both versatile and
vulnerable
The first 1000 DAYS of life therefore contains:
Risks with lifelong consequences for health and wellbeing
Chances to ‘get things right’ and to boost childrens’ development
Developmental Origins of Health and Disease (DOHaD) hypothesiss
The DOHaD hypothesis or Barker hypothesis: exposure to certain
environmental influences during critical or sensitive periods of
, development may have significant consequences on an individual’s
short and long-term health (basically the same as the 1000 years)
The earlier the better
The study gene-environment contributions to individual differences”
Adoption studies: compare characteristics of adopted children with
those of both their adoptive and biological parents
Twin studies: compare the similarities between identical and
fraternal twins reared together or apart
True or false??? Identical twins have identical genes. So, if reared
apart any similarities they have must be due to shared genes, not
shared environment it is often overlooked that identical twins
already shared the womb (prenatal environments)
How much of this environment they share depends on chorionic
arrangements
Chorionic arrangements
Dichorionic twins (1/3): separate placentas and separate fetal
circulations. Can be identical or fraternal twins (doctors like this one
the best)
Monochorionic twins (2/3): one placenta and one fetal circulation.
Can only be identical twins. Brings more risks of e.g. one baby being
smaller due to getting less nutrition
Greater concordance for MC identical twins than for DC identical
twins on:
o IQ scores
o Personality scores
o Schizophrenia
o Physiological measures
But even identical twins that:
o Shared the same placenta,
, o Shared the same circulation,
o And shared the same environment
Can be very different
Conjoined twins
Abby and Brittany Hensel
Each has a heart, stomach, spine, lungs, and spinal cord
Each twin feels and controls 1 arm and 1 leg
They can eat and write separately and simultaneously
Activities such as running, swimming, hair-brushing, playing piano or
volleyball, riding a bicycle requires coordination
Two driver’s licences, one is married
We are totally different persons
Differences e.g. due to self-organisation in the brain; connections
that are made in each brain
Summary:
Our biology and the environment interact, shaping our development
The first 1000 days play an important role in development
Many twin studies have underestimated the influence of prenatal
environment
More about the prenatal environment: next week!
Lecture 2: Prenatal development
Prenatal development
Sensitive period: window for the environment to shape fetal
development (chances & risks)
Teratogens: agent that cause deviations during prenatal
development (teratology or developmental toxicity)
Can cause structural malformations, but also manifestations such as
growth retardation and delays in mental development
Thalidomide
Anti-emetic drug, first used as tranquiliser, but soon also to treat
morning sickness
Virtually impossible to give rats a lethal dose
>10.000 children born with severe malformations to the limbs
(phocomelia): around 40% of them died around birth
