Unit 1 AP Psych 2025 (Units 1.1-1.3)

Nature

Predisposed biological characteristics that influence behavior and development.

Nurture

Society and cultural aspects that affect development and personality or behavior

Interactionalist Perspective

Genetics and environment both have their own influence that shape human behavior.

Evolutionary Prespective

Natural selection affects human behaviorand the survival of certain traits over generations.

Eugenics

Belief that people with “desirable” traits should reproduce to improve the genetic quality of the population. (Unethical and ignores scientific complexity of trait development).

Twin Studies

Research method for nature & nurture; Show effect of different environments on behavior, despite having similar genetic makeup.

Family Studies

Studies how traits run in a family by comparing members

Adoption Studies

Comparing adopted children’s behavior to biological & adoptive parents

• Similarity to biological = genes play bigger role

• Similarity to adoptive = environmental factors

Nervous System

Body’s communication network; made up of Central and Peripheral Nervous System

Central Nervous System (CNS)

Brain & spinal cord

Brain

“Command center” - controls thoughts, emotions, movement, breathing, & heart rate

Spinal Cord

Relays messages to and from brain to body; control reflexes WITHOUT input of brain

Peripheral Nervous System (PNS)

Carries messages to and from CNS to body

• Autonomic Nervous System

• Somatic Nervous System

Autonomic Nervous System

Controls involuntary body movements

• Parasympathetic

• Sympathetic

Sympathetic Nervous System

“Fight or Flight”; Prepares body for action in stress

Parasympathetic Nervous System

“Rest & Digest”; Brings body down from stress

Somatic Nervous System

Controls voluntary muscle movements

Neurons

Carry electrical & chemical signals

• Sensory Neurons

• Interneurons

• Motor Neurons

Reflex Arc

Rapid automatic responses that don’t require brain input

Sensory Neurons

Detect stimuli and send information to spi

Interneurons

Process and send information to motor neurons

Motor Neurons

Send signals to muscles and make them respond

Neural Transmission

Neuron → Depolarization → Refractory Period → Release of neurotransmitters

• At rest: neuron has stable charge

  • Stimulation → Neuron reaches threshold

• Depolarization

• Refractory Period

• Reuptake

Depolarization

Electrical signal travels down neuron

All or Nothing Principle

A neuron will either fire completely or not at all, there's no in-between.

Refractory Period

No firing occurs and neuron makes charges inside and outside neuron relatively stable

Reuptake

Neurotransmitters in synaptic gap are reabsorbed or broken down

Multiple Sclerosis

Protective covering of neurotransmitters is damaged. This slows neurotransmitter function down significantly and blocks signals. Caused by degradation of myelin sheath.

Myasthenia Gravis

Communication between neurons and muscles is disrupted leading to muscle weakness and fatigue.

Excitatory Neurotrasmitters

Make neuron more likely to fire

Inhibitory Neurons

Make neuron less likely to fire

Dopamine

Excitatory neurotransmitter; Regulates movement, motivation, and is like a reward system for the brain

Serotonin

Inhibitory neurotransmitter; Regulates mood, appetite, & sleep