Human Development

1
Human Development

• Biological Beginnings

2
The Evolutionary Perspective

• Charles Darwin The Origin of Species
• Natural selection genes which have survival
  value will be more abundant in the next
  generation
• Survival of the fittest individuals who survive
  are better adapted
• Those who survive reproduce and pass on their
  characteristics to the next generation

3
The Evolutionary Perspective

• Evolutionary psychology emphasizes adaptation,
  reproduction, and survival of the fittest in
  shaping behavior
• Using evolutionary principles to explain human
  behavior

4
Evolutionary Psychology

• Argument evolution shapes decision making,
  aggression, fears, mating/sexual behavior
• gene centered perspective
• epigentic perspective
• Critique deterministic downplays the role of
  culture and the environment

5
Chromosomes

• We start as a single cell, consisting of our
  entire genetic code
• Chromosomes located in the nucleus threadlike
  structures that carry our genes
• We have 46 chromosomes or 23 pairs
• 23 from mother, 23 from father
• The 23rd pair determines our sex

6
Genes and DNA

• Genes unit of hereditary information, composed
  of DNA each gene has its own function and
  location
• DNA contains genetic information and instructions

7
Cells, Chromosomes, Genes, and DNA
Nucleus (center of cell) contains chromosomes and
genes
Chromosomes are threadlike structures composed of
DNA molecules
Gene a segment of DNA (spiraled double chain)
containing the hereditary code
Fig. 2.3
8
Polygenetic Inheritance

• Polygenetic Inheritance when many genes interact
  to influence a characteristic
• Few behavioral traits are due to just one gene

9
Genes

• Human Genome Project
• Humans have 20,000-25,000 genes
• All humans genes are 99 the same
• Humans and apes share 96-98 of their genes

10
Nature vs. Nurture

• Nature the role of genes
• Nurture the role of the environment and external
  conditions
• Interactionist Perspective/Epigenetic View
  Both nature and nurture are important to
  development

11
Childhood AggressionThe Role of Nurture
(Garbarino, 2005)

• RISK FACTORS

• PROTECTIVE FACTORS

• Poverty
• Abuse
• Parental abandonment
• Large family size
• Parental addiction
• Experiencing racism
• Low educational attainment
• Spiritual emptiness

• Positive adult role models
• Intellectual achievement
• Reading for pleasure
• Playing an instrument
• Positive communication with parents
• Spirituality
• Believing we control our fate

12
Childhood Aggression The Role of Nature

• Nature
• Genetic Predisposition
• Abnormal MAOA gene

13
How Nature and Nurture Work Together

• Will a genetic predisposition for a certain
  behavioral trait lead to the expression of that
  trait?
• Answer it depends.

14
How Nature and Nurture Work Together

• Environmental influences (nurture) determine
  whether or not the gene is turned on
• Genes are NOT destiny

15
Epigenetic/Interactionist Perspective

• Development is the result of an ongoing,
  bidirectional interchange between heredity and
  environment

16
Behavioral Genetics

• A field that looks at the influence of heredity
  and environment
• Twin studies comparing identical and fraternal
  twins
• Adoption studies are children more similar to
  the biological or adoptive parent?

17
Behavioral GeneticsLimitations of Twin Studies

• Shared the environments siblings have in common
  (i.e. the household)
• Non-Shared influences outside the house peer
  groups, differential parental treatment, events
  experienced at school, etc.
• The role of environments

18
Behavioral GeneticsLimitations of Adoption
Studies

• Similarities between adoptive and biological
  parents
• Children may be placed in similar families

19
Niche-picking

• Niche-picking when children seeks out the
  environments they find appealing driven by their
  genes
• Example a child may inherit a trait like
  extraversion he/she will seek out highly social
  environments.

20
Genetic Disorders

• Down syndrome
• Extra copy of chromosome 21
• Very young mother or mothers over age 38 at
  greater risk

21
Sex-Linked Chromosome Abnormalities
22
The Course of Prenatal Development

• Germinal period 2 weeks after conception
  zygote is created, attaches to the uterine wall
• Embryonic period 2 to 8 weeks after conception
• Cell layers start to form organs
• Umbilical cord connects to placenta
• Fetal period
• From 2 months after conception to birth
• Trimesters of pregnancy

23
Prenatal Diagnostic Testing

• Amniocentesis samples amniotic fluid to check
  for chromosomal or metabolic disorders
• Genetic Counseling to understand a childs risk
  for inheriting a genetic disorders

24
Teratogens

• Teratogen agents that cause birth defects
• Severity of damage affected by
• Dose
• Genetic susceptibility
• Time of exposure

25
Teratogens

• Heavy drinking fetal alcohol syndrome (FAS)
  Facial deformities, low birth weight, respiratory
  problems
• Nicotine preterm births, low birth weight,
  respiratory problems, increased risk of SIDS
• Cocaine reduced birth weight, length, and head
  circumference
• Heroin behavioral problems, tremors, disturbed
  sleep, excessive crying, irritability
• Methamphetamine low birth weight, developmental
  and behavior problems

26
Teratogens

• Environmental hazards
• Lead
• Radiation
• Pesticides
• Carbon minoxide
• Mercury
• PCBs

• Infectious diseases
• AIDS
• STDs

27
Other Parental Factors

• Nutrition
• Children born to malnourished mothers are more
  likely to be malnourished/low birth weight
• Maternal Age
• Children born to adolescent mothers often
  premature, mortality rate is twice that of
  mothers in their twenties
• Mothers over 35 higher risk of infants with low
  birth weight or Down Syndrome

28
Other Parental Factors

• Emotional States/Stress Physiological changes
  affecting a mother during times of stress are
  transmitted to the fetus
• Mothers under stress are 4xs more likely to
  deliver early
• Stress puts mothers at risk for unhealthy
  behaviors
• Irregular contractions/difficult labor

29
Low birth weight

• Low brain weight and risk of brain injury
• Lung and liver disease
• ADHD and learning problems/disabilities
• Breathing problems and asthma
• Lower achievement levels
• Some effects can be reversed

30
Apgar Scale

• A scale used to assess the health of a newborn
  1-5 minutes after birth
• Measures heart rate, respiratory effort, muscle
  tone, body color, reflexes (2pts per category)
• Total score 7-10 indicates good condition 5
  indicates possible developmental difficulties 3
  or below signals an emergency

31
The Apgar Scale
Fig. 2.14
32
Bonding

• Needs to occur shortly after birth
• Early emotional attachments may create healthy
  interactions after leaving hospital
• Massages and tactile stimulation for premature
  infants affect development
• Research indicates that massage is particularly
  helpful for low birth weight infants