Disorders and defects are often product of recessive alleles.
Phenylketonuria (PKU) is a common defect (1 in 8000).
If both parents have recessive alleles = 1 in 4 children.
PKU is lack of enzymes that neutralizes phenylalanine (proteins) found in:
Chapter 2: Overview
The Birth Experience
The Newborn Infant
Results from the union of two gametes, the egg and the sperm
Gametes produced through specialized cell division, meiosis:
Each has only hal
Genes instruct the production of protein crucial for
DNA can duplicate itself mitosis. This allows a single celled ovum to
become a many-celled adult.
Largely control the continuous switching on and off of genes that
At 32 weeks gestation, the fetus decreases
responses to repeated or continued stimulation, a
simple form of learning called habituation
Newborn infants have been shown to recognize
Newborns also prefer smells, tastes, and
The Family Study
The mainstay of modern behavioral genetics research
A trait of interest is measured among groups of people who vary in
Correlations for traits measured for individuals who
Type of Studies
Males and females just as likely to inherit recessive disorders.
BUT, when harmful allele is carried in the X chromosome, X-linked
Females dominant X suppresses recessive X.
Males more likely affected: their sex ch
Some Environmental Hazards to Fetus or Newborn
Maternal alcoholism can lead to fetal alcohol syndrome (FAS), which is
associated with mental retardation, facial deformity, and other problems
Cigarette smoking during pregnancy is li
The Newborn Infant
Interacting with the Environment
State: The infants level of arousal and engagement in the environment
Ranges from deep sleep to intense activity
Is an important influence in the newborns exploration of the world
Six States of Arousa
Bipolar neurons have one axon and one dendrite.
They emerge from opposite sides of the cell body.
Bipolar neurons are found only as specialized
sensory neurons in the ey
Action potential. Unlike a graded potential, an
action potential is capable of traveling long distances. If a
depolarizing graded potential is
Repolarization. In response to the inflow of Na +,
K + channels open, this time allowing K + on the inside to rush out
of the cell. The movement of K + out of the cell causes
repolarization by restoring the original membrane polarization.
Unlike the re
Watsons exclusive emphasis on conditioning is now regarded as simplistic
However, his approach to extinguishing fear has been widely used to rid
people of phobias
This approach, known as
is a form of therapy
based on classical conditioning in w
Dwecks Social Cognitive Perspective
Emphasizes the role of self-attributions in academic achievement
Children with a mastery orientation attribute success and failure to the
amount of effort expended and persist in the face of failure
Children with a help
Dodges Information-Processing Theory of Social Problem Solving
analyzed childrens use of aggression as a problem-solving strategy.
and colleagues proposed that children go through six steps in solving
Characteristics of Some Families of Emotions
Smiling is the first clear sign of happiness that infants express
Young infants smile from their earliest days, but the meaning of their smiles
appears to change with age
are directed toward people an
A set of abilities that contribute to competent social functioning:
o Being able to motivate oneself and persist in the face of frustration
o Control impulses and delay gratification
o Identify and understand ones own and others fe
Ethological and Evolutionary Theories
The study of behavior within an ecological context.
behavior patterns were shaped by evolution just as physical
but they are drawn to visual and e
View of Childrens Nature
Central Developmental Issues
Skinners Operant Conditioning
Social Learning Theory
Emphasize the role of external factors in shaping personality and socia
Applies Darwinian concepts of natural
selection and adaptation to human behavior.
Basic idea is that certain genes predispose
individuals to behavior that enhances survival
E.g., obtaining food, avoiding predato
Eriksons Theory of Psychosocial Development
Erikson (19021994) had enormous influence on developmental psychology.
Proposed eight age-related development stages that span infancy to old
Each stage is characterized by a crisis, or task, that the indiv
Theories of Social Development
theories attempt to account for aspects of development such as
Theories of Social Cognition
Ecological Theories of De
Beyond IQ: The Development of Creativity
Creativity is often ignored in IQ tests. Why?
People who are a genius are often highly
Creativity in children: convergent and divergent thinking.
IQ and divergent