BIOLOGICAL BASES OF BEHAVIOR
HEREDITY AND ENVIRONMENT
Twin Case Studies
● There are two types of twins
1. Monozygotic Twins: Identical Twins
a. Born from the same egg
2. Dizygotic Twins: Fraternal Twins
a. Two different eggs
● Psychologists use twins to research the impact of evolution on the behavior
○ EX. If identical twins share more similarity in a trait than fraternal
twins, then the trait has a genetic component.
○ EX. If identical twins are raised apart and still show similarities, we
can say that genetics have a role in that trait.
Adoption Studies and Nature Debate
● Adoption studies measure how similar adoptees are to their biological and
adopted families.
● The argument between environment and genetics.
● Heritability: Measures how much the differences in someone's traits can be
attributed to genes.
● Evolutionary Psychology: Our genes cause us to act in ways that maximize
our survival.
Nervous System
● The Nervous System includes the brain, spinal cord, and the nerve network
○ Central Nervous System
○ Peripheral Nervous System
■ Somatic NS: voluntary motion ( EX. picking up a pencil)
● Motor Neurons (Efferent Neurons): how system receives
signals to move
● Sensory Neurons (Afferent neurons): how the systems
sends signals to the brain following sensation
■ Autonomic NS: involuntary regulation (EX. Breathing)
● Sympathetic: Fight or Flight (and Freeze) alert system
, ● Parasympathetic: Calming and digestion
Endocrine System (Not a nervous system)
● This system is responsible for circulating hormones through the body using
blood
○ Hormones affect behaviors, mood, motivation, and consciousness
■ Pituitary Gland: regulates the endocrine system
■ Pineal Glands: in the brain and secretes melatonin
■ Hypothalamus: in the brain; takes orders from the pituitary
gland
■ Thyroid and parathyroid glands: secrete thyroid and
parathyroid hormones
■ Adrenal Glands: secrete hormones related to fight or flight
response
■ Pancreas: secretes insulin and glucagon to regular blood glucose
levels
, Limbic System
● The limbic system is in charge of
memory, emotion/emotional responses,
and behavioral responses
○ Ventromedial Hypothalamus:
controls your fullness
● The behaviors include
○ Feeding
○ Reproduction
○ Fight or flight Response
● The emotions include
○ Pleasure
○ Fear
○ Anxiety
○ Anger
● Emotional attachment to the content of a
memory is usually associated with
amygdala.
○ Associated with fear
The Brain (Know the basic parts and functions)
1. Frontal Lobe
2. Occipital Lobe
3. Temporal Lobe
4. Parietal lobe
5. Thalamus
6. Broca’s Area
7. Thalamus
8. Wenicke’s Area
9. Motor Cortex
10. Somatosensory Cortex
11. Primary Auditory Cortex
12. Primary Visual Cortex
13. Corpus Callosum
, 14. Olfactory bulb
15. Brain Stem
16. Medulla Oblongata
17. Pons
18. Reticular Activating System
19. Cerebellum
20. Amygdala
21. Limbic
22. Forebrain
23. Hindrain
24. Midbrain
Brain Parts Study guide with Definitions and Examples
Brain Lateralization: Split Brain
● The 2 hemispheres can operate separately
○ Separate streams of consciousness
○ Connected by the corpus callosum
○ If the corpus callosum is detached, the hemispheres can no longer
communicate
● Left Hemisphere
○ Recognize words and letters
○ Language
○ Verbal memory and finding meaning
○ Speech, reading, writing
● Right Hemisphere
○ Faces, patterns, etc
○ Other sounds (EX Music)
○ Nonverbal memory and non perceptual meaning
○ Spatial reasoning, rotating objects in the mind, direction or distance
CT Scans
● A CT (computerized tomography) scan can be used to visualized almost
every part of your body
● Uses radioactive waves and usually used to find broken bones and cancer
HEREDITY AND ENVIRONMENT
Twin Case Studies
● There are two types of twins
1. Monozygotic Twins: Identical Twins
a. Born from the same egg
2. Dizygotic Twins: Fraternal Twins
a. Two different eggs
● Psychologists use twins to research the impact of evolution on the behavior
○ EX. If identical twins share more similarity in a trait than fraternal
twins, then the trait has a genetic component.
○ EX. If identical twins are raised apart and still show similarities, we
can say that genetics have a role in that trait.
Adoption Studies and Nature Debate
● Adoption studies measure how similar adoptees are to their biological and
adopted families.
● The argument between environment and genetics.
● Heritability: Measures how much the differences in someone's traits can be
attributed to genes.
● Evolutionary Psychology: Our genes cause us to act in ways that maximize
our survival.
Nervous System
● The Nervous System includes the brain, spinal cord, and the nerve network
○ Central Nervous System
○ Peripheral Nervous System
■ Somatic NS: voluntary motion ( EX. picking up a pencil)
● Motor Neurons (Efferent Neurons): how system receives
signals to move
● Sensory Neurons (Afferent neurons): how the systems
sends signals to the brain following sensation
■ Autonomic NS: involuntary regulation (EX. Breathing)
● Sympathetic: Fight or Flight (and Freeze) alert system
, ● Parasympathetic: Calming and digestion
Endocrine System (Not a nervous system)
● This system is responsible for circulating hormones through the body using
blood
○ Hormones affect behaviors, mood, motivation, and consciousness
■ Pituitary Gland: regulates the endocrine system
■ Pineal Glands: in the brain and secretes melatonin
■ Hypothalamus: in the brain; takes orders from the pituitary
gland
■ Thyroid and parathyroid glands: secrete thyroid and
parathyroid hormones
■ Adrenal Glands: secrete hormones related to fight or flight
response
■ Pancreas: secretes insulin and glucagon to regular blood glucose
levels
, Limbic System
● The limbic system is in charge of
memory, emotion/emotional responses,
and behavioral responses
○ Ventromedial Hypothalamus:
controls your fullness
● The behaviors include
○ Feeding
○ Reproduction
○ Fight or flight Response
● The emotions include
○ Pleasure
○ Fear
○ Anxiety
○ Anger
● Emotional attachment to the content of a
memory is usually associated with
amygdala.
○ Associated with fear
The Brain (Know the basic parts and functions)
1. Frontal Lobe
2. Occipital Lobe
3. Temporal Lobe
4. Parietal lobe
5. Thalamus
6. Broca’s Area
7. Thalamus
8. Wenicke’s Area
9. Motor Cortex
10. Somatosensory Cortex
11. Primary Auditory Cortex
12. Primary Visual Cortex
13. Corpus Callosum
, 14. Olfactory bulb
15. Brain Stem
16. Medulla Oblongata
17. Pons
18. Reticular Activating System
19. Cerebellum
20. Amygdala
21. Limbic
22. Forebrain
23. Hindrain
24. Midbrain
Brain Parts Study guide with Definitions and Examples
Brain Lateralization: Split Brain
● The 2 hemispheres can operate separately
○ Separate streams of consciousness
○ Connected by the corpus callosum
○ If the corpus callosum is detached, the hemispheres can no longer
communicate
● Left Hemisphere
○ Recognize words and letters
○ Language
○ Verbal memory and finding meaning
○ Speech, reading, writing
● Right Hemisphere
○ Faces, patterns, etc
○ Other sounds (EX Music)
○ Nonverbal memory and non perceptual meaning
○ Spatial reasoning, rotating objects in the mind, direction or distance
CT Scans
● A CT (computerized tomography) scan can be used to visualized almost
every part of your body
● Uses radioactive waves and usually used to find broken bones and cancer
