Unit 1: Biological Bases of Behavior

1.1,

Nature-nurture Issue

The long-standing controversy over the relative contributions that genes and experience make to the development of psychological traits and behaviors.

Nature

Genes; biochemical units of heredity that make up the chromosomes; Passed to you from parents. Genes influence biological development.

Nurture

Environment; every non-genetic influence from prenatal nutrition to the people and things around us.

Natural Selection

The principle that among the range of inherited trait variations, those of reproduction will be passed on.

Behavior Genetics

The study of the relative power and limits of genetic and environmental influences on behavior.

Environment

Every external influence, from prenatal nutrition to the people and things around us.

Genes

The biochemical units f heredity that make up the chromosomes; segments of DNA capable of synthesizing proteins; 4 letter codes; A, C, G, T

Genome

The complete instruction for making an organism consisting of all the genetic material in that organism’s chromosomes.

Identical Twins (Monozygotic)

Twins who develop from a single fertilized egg that splits in two, creating two genetically identical organisms.

Fraternal Twins (Dizygotic)

Twins who develop from separate fertilized eggs; are genetically no closer than brothers and sisters, but they share a fetal environment; DIFFERENT

Heredity

The passing on of physical or mental characteristics genetically from one generation to another.

Heritablity

The proportion of variation among individuals that we can attribute to genes. The heritability of a trait can vary.

Interaction

The interplay that occurs when the effect of one factor depends on another factor.

Epigenetics

The study of environmental expression that occurs without a DNA change.

Evolutionary Psychologists

The study of the evolution of behavior and the mind, using principles of natural selection.

Predispotion

The possibility exists; passed through DNA to future generations.

Natural Selection

The principles that, among the range of inherited trait variations, those contributing to reproduction and survival will most likely be passed on to succeeding generations.

Mutations

Random errors in gene replication that leads to a change; the source of all genetic diversity.

Nervous System

Consists of all the nerve cells; body’s speedy, electrochemical communication system; Two major components.

Central Nervous System

The brain and your spinal cord; Interneurons

Peripheral Nervous System (PNS)

The motor and sensory neurons that connects the central nervous to the rest of your body.

Nerves

Bundled axons that form neutral “cables” connecting the central nervous system with muscles, glands, and sense organs.

Sensory Neurons

Afferent; Neurons that carry incoming information from the sensory receptors to the brain and spinal cord.

Motor Neurons

Efferent; Neurons that carry outgoing information from the brain and the spinal cord to the muscles and glands.

Interneurons

Neurons within the brain/spinal cord that communicate internally and intervene between the sensory inputs and motor outputs.

Somatic Nervous System

The division of the peripheral nervous system (PNS) that controls the body’s skeletal muscles.

Autonomic Nervous System

“Arouses”; (fight or flight); mobilizing its energy in stressful situations.

Parasympathetic Nervous System

“Clams”; (rest and digest); Clams the body reserving its energy.

Reflex

A simple, automatic response to a sensory stimulus, such as the knee-jerk response.

Endocrine System

The body’s “slow” chemical communications system; a set of glands that secrete hormones into the bloodstream.

Hormones

Chemical messengers that are manufactured by the endocrine glands travel through the bloodstream and affect other tissues.

Adrenal Glands

A pair of endocrine glands that sit just above the kidneys, and secrete hormones(epinephrine and norepinephrine) that help arouse the body in times of stress.

Pituitary Gland

The endocrine system’s most influential gland. Under the influence of the hypotholamus, the pituitary regulates growth and controls other endocrine glands.

Neurotransmitters

The chemical messengers that diffuse across a synapse and excite or inhibit an adjacent neuron

Action Potential

The neural impulse; A brief electrical charge that travels down a axon

All-or-nothing Principle

A neuron always fires with the same intensity; not soft then hard or hard then soft

Depolarization 

A change with a cell, during which the cell undergoes a shift in electric charge distribution, resulting in less than negative charge in than the outside

Reuptake

A neurotransmitter’s resorption by the sending neuron

Multiple Sclerosis

When the myelin sheath degenerates, communications to muscles slow, with eventual loss of muscle control

Excitatory Neurotransmitters

Effect; makes it more likely that the receiving neuron will generate an action potential or “fire”

Dopamine

Neurotransmitter that influences learning, attention, and emotion

Norepinephrine

Arousal and vigilance

GABA (gamma-aminobutyric acid)

Inhibition of action potential’s anxiety and intoxication

Substance P

Pain perception; mood and anxiet

Hormones

Chemical messengers that are manufactured by the endocrine glands travel through the bloodstream and effect other tissues.

Refractory Period 

The brief instant when a new action potential cannot be generated because neuron is recharging from previous action potential

Resting Potential

The state of a neuron when it is “changed” but, waiting for the next action potential to be generated

Inhibitory Neurotransmitters

Effect; makes it less likely that a receiving neuron will generate an action potentials or “fire”

Serotonin

Neurotransmitter that affects hunger, sleep, arousal, and mood

Glutamate

Enhances action potentials’ Learning and memory

Endorphins

Pain reduction; Reward