Introduction to Psychology
What is psychology?
Book definition psychology is the scientific study of mind, brain and behaviour.
Other definition psychology is the scientific study of mind and brain to explain behaviour.
We study the mind and brain, so we are able to predict behaviour, and to predict behaviour
we need to understand the underlining mind and brain.
We need a science to study behaviour because common sense fails. For example: in general
people tend to accept very general fake personality descriptions as very accurate
personality descriptions of their own personality.
Topic 1 – Genes and evolution
Questions:
1. What are chromosomes, DNA and genes and what is the relationship between the
three?
2. What is meant by genetic expression, genotype and phenotype?
3. Can you explain how genes are passed from parents to children?
4. Which role do evolution, genes and environment play in behavior?
5. What are behavioral genetics and which methods are used here?
6. What is meant by heritability?
Can you claim that “a violent person has violent genes”?
Seventies No! Violent behavior is caused by environment
- violence was seen as a product of capitalism or bad parenting
Nineties yes! Violent behavior is caused by genes
- Gene studies were now possible due to the development of genetic
techniques
- The common point of view was that children turn out the way they do
because of their gene. Good parenting will not make any difference
Today violent behavior is the result of the interaction between genes and
environment.
The genetic basis
Every human cell has a nucleus
Each nucleus contains 46 chromosomes
Chromosomes carry instructions for how to build and operate a body
Chromosomes are made up of coiled strands of DNA
The DNA molecule has a double helix shape
The specific sequence of bases along the backbone of the DNA strand provides codes
for specific proteins, however only the meaningful parts of the sequence will code
for a protein.
, Chromosomes are made of DNA, and genes are specific sequences of DNA that
encode particular proteins. Genes are located on chromosomes, and the
arrangement of these genes forms the genotype.
Genes = the meaningful sections (sequences that code for proteins) of the DNA molecule
They govern the cell’s functioning by providing instructions for making proteins.
The presence of a specific gene does not necessarily mean that the protein is being
produced: gene can be expressed or not expressed.
Gene expression
= whether a gene is turned “on” or “Off” = the extent to which a gene is transcribed into a
sequence of amino acids (proteins).
The specific pattern of a gene expression leads to different cells
Turn off methylation of the gene sequence leading to the inability to be
transcribed.
In every cell, some genes are expressed, and others are not. Whether a gene is
expressed or not is controlled by the biochemical environment inside the cell,
- Which in turn, is influenced by the environment outside the cell, timing in
development, the overall environment, experience, behavior.
- The outside environment can also lead to changes in the environment inside
your body which can lead to altering gene expression
Genotype = an organism’s set of genes
Phenotype = the observable physical and behavioral traits of an organism
Determined by the interaction between genotype and environment
Example: monozygotic twins have the same genotype but since they live in different
environments it will lead to a different phenotype, such as different looks and
behavior.
Each gene is paired with another gene
o We get 23 chromosomes from each parent
o Gene pairs are located at corresponding positions on pairs of chromosomes
An allele = a specific variant of a gene
Dominant = shows its effects in phenotype independent from the other allele
, Recessive = only shows their effect in the phenotype if the other allele is also
recessive.
Homozygote alleles on locus are the same
Heterozygote alleles on locus are different
A trait or behavior is determined by the interaction between the environment and:
- One gene pair
- Multiple gene pairs polygenetic influence
Darwin’s evolution theory:
The complete set of genes of an organism have been developed by evolution
According to Darwin, all modern organisms:
Have descended from a small set of shared ancestors
Have merged over time through the process of evolution
Evolution through natural selection: three conditions
1. There is variation of alleles among a population
2. Individuals with a certain trait, survive and reproduce at higher rates than others
3. The trait associated with this advantage is passed from parents to offspring
Survival of genes, not of individuals
Evidence for modern evolutionary theory:
Fossil record fossils gradually change along heritage lines and there are
transitions forms between different species
Resemblance between genomes of various organisms (species) genomes of
humans are very similar to anthropoid apes. In fact, chromosome n2 of humans is a
combination of two anthropoid apes’ chromosomes.
Pseudogenes = inactive genes that do not produce any proteins anymore but
probably did in our ancestors.
- Vitamin C from glucose to convert glucose into vitamin C there are 4
enzymes participating in each step. Humans do not have the enzyme for the
fourth step; however the DNA sequence of the enzyme is present but with a
mutation in the gene.
Distribution of species across the world
- Continental islands large variety of species
- Oceanic islands only flies and birds because they were not connected to
the main continent
A lot of people still do not believe in evolution. They believe in intelligent design based on
faith.
Evolution does not mean that:
, Improves organisms it only makes organism more adapted to their environment.
If environment changes, the adaptation could be harmful for us (liking sweets
eating too many leads to cardiovascular diseases)
leads to rigid behavioral patterns organisms develop in a continuously changing
environment and thus we can become very flexible and adaptive
Nature vs nurture
Who we are is determined by how our genes are expressed in different environments
A study:
Hypothesis the MAOA gene regulates enzyme monoamine oxidase (MAO) and may be
important in determining susceptibility to the effect of maltreatment because low levels of
MAO have been implicated in aggressive behaviors.
Research method group of 1000 were followed from birth to adulthood
researchers measured which children were mistreated by their parents
environmental measure (nurture)
researchers measure the presence of the MAOA gene, which comes in two forms:
one leads to high levels of MAO and the other leads to low levels of MAO gene
measurement (nature)
then they measured the tendency toward criminal behavior
Results:
those who has the MAOA gene for low MAO activity were much more likely to have
been convicted of violent crimes if they had been maltreated as children. The
effects of maltreatment had less influence on those with high MAO gene
it was not the gene (low MAOA) by itself that lead to the probability of getting
convicted for criminal behavior, and it was not the environment (maltreatment) on
its own but a combination of the two.
nature and nurture can work together to affect human behavior
What is psychology?
Book definition psychology is the scientific study of mind, brain and behaviour.
Other definition psychology is the scientific study of mind and brain to explain behaviour.
We study the mind and brain, so we are able to predict behaviour, and to predict behaviour
we need to understand the underlining mind and brain.
We need a science to study behaviour because common sense fails. For example: in general
people tend to accept very general fake personality descriptions as very accurate
personality descriptions of their own personality.
Topic 1 – Genes and evolution
Questions:
1. What are chromosomes, DNA and genes and what is the relationship between the
three?
2. What is meant by genetic expression, genotype and phenotype?
3. Can you explain how genes are passed from parents to children?
4. Which role do evolution, genes and environment play in behavior?
5. What are behavioral genetics and which methods are used here?
6. What is meant by heritability?
Can you claim that “a violent person has violent genes”?
Seventies No! Violent behavior is caused by environment
- violence was seen as a product of capitalism or bad parenting
Nineties yes! Violent behavior is caused by genes
- Gene studies were now possible due to the development of genetic
techniques
- The common point of view was that children turn out the way they do
because of their gene. Good parenting will not make any difference
Today violent behavior is the result of the interaction between genes and
environment.
The genetic basis
Every human cell has a nucleus
Each nucleus contains 46 chromosomes
Chromosomes carry instructions for how to build and operate a body
Chromosomes are made up of coiled strands of DNA
The DNA molecule has a double helix shape
The specific sequence of bases along the backbone of the DNA strand provides codes
for specific proteins, however only the meaningful parts of the sequence will code
for a protein.
, Chromosomes are made of DNA, and genes are specific sequences of DNA that
encode particular proteins. Genes are located on chromosomes, and the
arrangement of these genes forms the genotype.
Genes = the meaningful sections (sequences that code for proteins) of the DNA molecule
They govern the cell’s functioning by providing instructions for making proteins.
The presence of a specific gene does not necessarily mean that the protein is being
produced: gene can be expressed or not expressed.
Gene expression
= whether a gene is turned “on” or “Off” = the extent to which a gene is transcribed into a
sequence of amino acids (proteins).
The specific pattern of a gene expression leads to different cells
Turn off methylation of the gene sequence leading to the inability to be
transcribed.
In every cell, some genes are expressed, and others are not. Whether a gene is
expressed or not is controlled by the biochemical environment inside the cell,
- Which in turn, is influenced by the environment outside the cell, timing in
development, the overall environment, experience, behavior.
- The outside environment can also lead to changes in the environment inside
your body which can lead to altering gene expression
Genotype = an organism’s set of genes
Phenotype = the observable physical and behavioral traits of an organism
Determined by the interaction between genotype and environment
Example: monozygotic twins have the same genotype but since they live in different
environments it will lead to a different phenotype, such as different looks and
behavior.
Each gene is paired with another gene
o We get 23 chromosomes from each parent
o Gene pairs are located at corresponding positions on pairs of chromosomes
An allele = a specific variant of a gene
Dominant = shows its effects in phenotype independent from the other allele
, Recessive = only shows their effect in the phenotype if the other allele is also
recessive.
Homozygote alleles on locus are the same
Heterozygote alleles on locus are different
A trait or behavior is determined by the interaction between the environment and:
- One gene pair
- Multiple gene pairs polygenetic influence
Darwin’s evolution theory:
The complete set of genes of an organism have been developed by evolution
According to Darwin, all modern organisms:
Have descended from a small set of shared ancestors
Have merged over time through the process of evolution
Evolution through natural selection: three conditions
1. There is variation of alleles among a population
2. Individuals with a certain trait, survive and reproduce at higher rates than others
3. The trait associated with this advantage is passed from parents to offspring
Survival of genes, not of individuals
Evidence for modern evolutionary theory:
Fossil record fossils gradually change along heritage lines and there are
transitions forms between different species
Resemblance between genomes of various organisms (species) genomes of
humans are very similar to anthropoid apes. In fact, chromosome n2 of humans is a
combination of two anthropoid apes’ chromosomes.
Pseudogenes = inactive genes that do not produce any proteins anymore but
probably did in our ancestors.
- Vitamin C from glucose to convert glucose into vitamin C there are 4
enzymes participating in each step. Humans do not have the enzyme for the
fourth step; however the DNA sequence of the enzyme is present but with a
mutation in the gene.
Distribution of species across the world
- Continental islands large variety of species
- Oceanic islands only flies and birds because they were not connected to
the main continent
A lot of people still do not believe in evolution. They believe in intelligent design based on
faith.
Evolution does not mean that:
, Improves organisms it only makes organism more adapted to their environment.
If environment changes, the adaptation could be harmful for us (liking sweets
eating too many leads to cardiovascular diseases)
leads to rigid behavioral patterns organisms develop in a continuously changing
environment and thus we can become very flexible and adaptive
Nature vs nurture
Who we are is determined by how our genes are expressed in different environments
A study:
Hypothesis the MAOA gene regulates enzyme monoamine oxidase (MAO) and may be
important in determining susceptibility to the effect of maltreatment because low levels of
MAO have been implicated in aggressive behaviors.
Research method group of 1000 were followed from birth to adulthood
researchers measured which children were mistreated by their parents
environmental measure (nurture)
researchers measure the presence of the MAOA gene, which comes in two forms:
one leads to high levels of MAO and the other leads to low levels of MAO gene
measurement (nature)
then they measured the tendency toward criminal behavior
Results:
those who has the MAOA gene for low MAO activity were much more likely to have
been convicted of violent crimes if they had been maltreated as children. The
effects of maltreatment had less influence on those with high MAO gene
it was not the gene (low MAOA) by itself that lead to the probability of getting
convicted for criminal behavior, and it was not the environment (maltreatment) on
its own but a combination of the two.
nature and nurture can work together to affect human behavior
