Bio Psychology – Chapter 1 “The Biological Approach to Psychology”
Study of the animal roots of behavior, relating actions and experiences to
genetics and physiology
The biological approach to behavior
o Leibniz (1714) posed in regards to the universe:
“Why is there something rather than nothing?”
The univers had to be self-created
o The universe could have taken on many different forms; very few
could have supported life
o We may never know why the universe is the way it is
o Chalmers (1995) proposes the “hard problem”:
Given a universe of matter and energy, why is there such a
thing as consciousness?
o A question of the relationship between physics and psychology
o Biological explanations of behavior raise the issue of the relationship
between mental activity and the brain aka the “mind-body” or
“mind-brain problem”
o Consciousness as a fundamental property; it just exists
o Biological psychology: the study of the physiological, evolutionary
and developmental mechanisms of behavior and experience
o A strong emphasis is placed upon brain functioning (Lecture 1, 6)
o Brain functioning can be explained at a more microscopic level in
terms of neuron and glia activity
o Neurons and glia somehow produce an enormous wealth of behavior
and experience
Biological explanations of behavior
o Biological explanations of behavior fall into four categories:
Physiological: relates a behavior to the activity of the brain
and other organs
Ontogenetic: describes the development of a structure or
behavior (genes, nutrition, experiences)
Evolutionary: reconstructs evolutionary history of a behavior
or structure
Functional: describes why a structure or behavior evolved as
it did
Genetics and behavior
o Both genes and environment interact to shape human behavior
o The fundamental issue is how much a role each factor plays in
shaping human behaviors
o Examples: psychological disorders, weight gain, personality, sexual
orientation
Mendelian genetics
o 19th century monk Gregor Mendel demonstrated that inheritance
occurs through genes
o Genes are aligned along chromosomes (strands of genes) and come
in pairs
o A gene is a portion of a chromosome and is composed of
deoxyribonucleic acid (DNA)
o DNA serves as a model for the synthesis of ribonucleic acid (RNA)
, o RNA is a single strand chemical that can serve as a template/ model
for the synthesis of proteins
Contains adenine, guanine, cytosine and thymine determining
the order of amino acids that compose a protein
o Proteins determine the development of the body by:
Forming part of the structure of the body
Serving as enzymes, biological catalysts that regulate
chemical reactions
o
o Homozygous, for, a gene means that a person has an identical pair
of genes on the two chromosomes
o Heterozygous, for a gene, means that a person has an unmatched
pair of genes on the two chromosomes
o Genes are either dominant, recessive, or intermediate
Examples: eye color, ability to taste PTC
A dominant gene has a strong effect in both the homozygous
or heterozygous condition
A recessive gene shows its effect only in the homozygous
condition
Examples such as PTC and hair color can be misleading
Implies that a single gene combination completely controls a
characteristic, but this is not true
o Some genes are only expressed partly: in some cells and not others
or only under certain circumstances
o Types of genes include:
Autosomal genes: all other genes except for sex- linked
genes
Sex-linked genes: genes located on the sex chromosomes
o During reproduction:
Females contribute an X chromosome
Males contribute either an X or a Y chromosome that
determines the sex
o The human Y chromosome has genes for 27 proteins
o The human X chromosome has genes for approximately 1500
proteins
o Thus, sex-linked genes usually refer to X-linked genes: e.g., red-
green color deficiency)
o Sex-limited genes: present in both sexes but mainly have an
effect on one sex (chest hair, breast size, etc.)
Study of the animal roots of behavior, relating actions and experiences to
genetics and physiology
The biological approach to behavior
o Leibniz (1714) posed in regards to the universe:
“Why is there something rather than nothing?”
The univers had to be self-created
o The universe could have taken on many different forms; very few
could have supported life
o We may never know why the universe is the way it is
o Chalmers (1995) proposes the “hard problem”:
Given a universe of matter and energy, why is there such a
thing as consciousness?
o A question of the relationship between physics and psychology
o Biological explanations of behavior raise the issue of the relationship
between mental activity and the brain aka the “mind-body” or
“mind-brain problem”
o Consciousness as a fundamental property; it just exists
o Biological psychology: the study of the physiological, evolutionary
and developmental mechanisms of behavior and experience
o A strong emphasis is placed upon brain functioning (Lecture 1, 6)
o Brain functioning can be explained at a more microscopic level in
terms of neuron and glia activity
o Neurons and glia somehow produce an enormous wealth of behavior
and experience
Biological explanations of behavior
o Biological explanations of behavior fall into four categories:
Physiological: relates a behavior to the activity of the brain
and other organs
Ontogenetic: describes the development of a structure or
behavior (genes, nutrition, experiences)
Evolutionary: reconstructs evolutionary history of a behavior
or structure
Functional: describes why a structure or behavior evolved as
it did
Genetics and behavior
o Both genes and environment interact to shape human behavior
o The fundamental issue is how much a role each factor plays in
shaping human behaviors
o Examples: psychological disorders, weight gain, personality, sexual
orientation
Mendelian genetics
o 19th century monk Gregor Mendel demonstrated that inheritance
occurs through genes
o Genes are aligned along chromosomes (strands of genes) and come
in pairs
o A gene is a portion of a chromosome and is composed of
deoxyribonucleic acid (DNA)
o DNA serves as a model for the synthesis of ribonucleic acid (RNA)
, o RNA is a single strand chemical that can serve as a template/ model
for the synthesis of proteins
Contains adenine, guanine, cytosine and thymine determining
the order of amino acids that compose a protein
o Proteins determine the development of the body by:
Forming part of the structure of the body
Serving as enzymes, biological catalysts that regulate
chemical reactions
o
o Homozygous, for, a gene means that a person has an identical pair
of genes on the two chromosomes
o Heterozygous, for a gene, means that a person has an unmatched
pair of genes on the two chromosomes
o Genes are either dominant, recessive, or intermediate
Examples: eye color, ability to taste PTC
A dominant gene has a strong effect in both the homozygous
or heterozygous condition
A recessive gene shows its effect only in the homozygous
condition
Examples such as PTC and hair color can be misleading
Implies that a single gene combination completely controls a
characteristic, but this is not true
o Some genes are only expressed partly: in some cells and not others
or only under certain circumstances
o Types of genes include:
Autosomal genes: all other genes except for sex- linked
genes
Sex-linked genes: genes located on the sex chromosomes
o During reproduction:
Females contribute an X chromosome
Males contribute either an X or a Y chromosome that
determines the sex
o The human Y chromosome has genes for 27 proteins
o The human X chromosome has genes for approximately 1500
proteins
o Thus, sex-linked genes usually refer to X-linked genes: e.g., red-
green color deficiency)
o Sex-limited genes: present in both sexes but mainly have an
effect on one sex (chest hair, breast size, etc.)
