Unit 1: Biological Bases of Behavior

Topic 1: Interaction of Heredity and Environment

Nature-Nurture issue

Longstanding controversy over the relative contributions that genes and experience make to the development of psychological traits and behaviors

Natural Selection

Charles Darwin Pioneered this idea which is that inherited traits enabling an organism to survive and reproduce in a particular environment will most likely be passed on to succeeding generations

Mutations

A random error in gene replication that leads to change

Our similarities arise form our shared __________

Genome

How did we develop this shared human genome

Through natural selection, whoever had the better instincts survived to pass the genome

Behavior Genetics

The genetic and environmental roots of human differences

Heredity influence on behavior

Provides genetic traits such as temperament, intelligence potential, and physical abilities.

Environmental influence on behavior

Help shape how the trat develop such as family, culture, education, and life experiences

Chromosomes

Thread-like structures in the nucleus of cells that carry genetic information and play a foundational role in shaping psychological traits, behaviors, and predispositions to mental health conditions. 23 from mothers egg and 23 from the fathers sperm: 46 chromosomes in total

What does it mean when genes are “turned on”? ;)

20,00 genes are either active or inactive. When genes are activated, they provide the code for creating protein molecules, the body’s building blocks

Traits influenced by genes?

Eye color, height, hair color, and risk for certain diseases, etc

Identical Twins

Develop from a single fertilized egg

Fraternal Twins

Develop from two different eggs

First researcher to study twins reared apart? Findings?

Thomas Bouchard. Found similarities in taste, physical attributes, personality, abilities, attitudes, interests, and fears

Effect of an adoptive family on the adoptees’ personality?

More self-giving and unselfish, scored higher on intelligence tests, and mostly grew into happier and more stable adults

Interaction

The interplay that occurs when the effect of one factor (such as environment) depends on another as heredity

Epigenetics

“Above” or “in addition to” genetics; the study of the molecular mechanisms by which environments can influence genetic expression (without a DNA change)

Nature via Nurture

our environment shape and develop our genetic traits. Heredity provides potential, but environmental influences can trigger that potential

Topic 2: Overview of the Nervous System

Nervous System

The body’s electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems

Central Nervous System

Comprising the brain and spinal cord, serves as the primary control center for psychological and physiological processes (body decision maker)

Nerves

Bundled axons that form neural cables

Sensory Neurons

Carry messages from the body’s tissues and sensory receptors

Motor Neurons

Carry instructions from the central nervous systems (CVS) to the body’s muscles and glands

Interneurons

Between the sensory input and motor output where information is processed

Three types of nerves

Sensory, motor, interneurons

Components of peripheral nervous system

Somatic, autonomic, sympathetic, parasympathetic

Somatic Nervous System

Division of the peripheral nervous system that controls the body’s skeletal muscles

Autonomic Nervous System

The part of peripheral nervous system that controls the glands and muscles of the internal organs

Sympathetic nervous System

The division of the autonomic nervous system that arouses the body, mobilizing its energy

Parasympathetic Nervous System

The division of the autonomic nervous system that calms the body, conserving its energy