PSY 101 Chapter Notes - Chapter 2: Peristalsis, Vasoconstriction, Man Seeking Woman
INTRODUCTION TO PSYCHOLOGY
Chapter 2: Evolution and the Biological Roots of Behavior
At the end of this Chapter you should be able to:
• Learn about evolutionary roots of motivated behavior
• Learn about Eating
• Learn about Threat and Aggression
• Learn about Mating
Charles Darwin
• Rattled the world with his theory of natural selection
• Wrote “Origin of Species”
Darwin’s Theory of Evolution
1. More individuals are born in each species that survive to sexual maturity.
2. There is variation among the individuals of all species; indeed, no two individuals are
identical.
3. Certain diff among individuals are adaptive. The individuals who possess the adaptive
characteristics are more likely to survive and reproduce in the environment into which they
are born.
4. Some adaptive differences among individuals are inherited.
5. Darwin’s Theory of Evolution
6. The environment does not contain enough resources to support all individuals.
7. A struggle for existence occurs among individuals; those who possess the most adaptive
characteristics, by definition, win the struggle.
8. Individuals who survive and reproduce pass on their adaptive characteristics to their
offspring, who are more inclined to inherit these adaptive traits than the offspring of parents
who do not possess them.
9. Over many generations, this process may result in the creation of new species.
Biological Perspective
• The biological perspective leads us to ask how various behaviors came to be – how they
evolved and what purpose they serve.
• What do we share with other species – e.g., A sense of curiosity, a sense of play etc…
• What do we not share with other species – e.g., language?
Evolution of Behavior
• Many aspects of who we are and how we behave are rooted in our genetic heritage.
• Identical twins inherit exactly the same genetic pattern. This makes a difference! Identical
twins usually end up more similar to each other in their personalities and preferences than are
other siblings, even when they are raised apart (in different households).
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Evolution of Behavior: The Comparative Method
• We can get further insights into the evolution of behavior by comparing human behavior to
other organisms.
• If we find parallels between, say, human aggression and aggression in other species, this
would strengthen the belief that OUR aggression is fueled by genetic forces that operate on
all species.
• Other animals are less likely to be influenced by cultural factors / complex decision-
making. Therefore finding parallels with other species would suggest a smaller role for
these human (cultural) influences.
The Autonomic Nervous System
• All mammals (and all birds) are endotherms; organisms that maintain stable body heat.
• Endothermic animals sometimes become too warm ; and so need to lose heat and sometimes
too cold and so preserve the heat created by their own metabolic activity
• These two activities are controlled by the autonomic nervous system
•Central Nervous System (CNS) - The brain and spinal cord
•Peripheric Nervous System (PNS)
• System of nerves outside of the brain and spinal cord
• Send control to the glands and smooth muscles
• Controls internal organs, usually not under voluntary control
• The peripheral nervous system is subdivided into the:
• sensory-somatic nervous system and the
• autonomic nervous system
• 2 branches
• Sympathetic
• Parasympathetic
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Chapter 2: evolution and the biological roots of behavior. At the end of this chapter you should be able to: learn about evolutionary roots of motivated behavior, learn about eating, learn about threat and aggression, learn about mating. Charles darwin: rattled the world with his theory of natural selection, wrote origin of species . Darwin"s theory of evolution: more individuals are born in each species that survive to sexual maturity, there is variation among the individuals of all species; indeed, no two individuals are identical, certain diff among individuals are adaptive. Evolution of behavior: many aspects of who we are and how we behave are rooted in our genetic heritage. Identical twins inherit exactly the same genetic pattern. Identical twins usually end up more similar to each other in their personalities and preferences than are other siblings, even when they are raised apart (in different households).
