biological basis of behavior

lecture 1 - august 26 2026

nature versus nurture

surroundings, stress, and family life change how genetic instructions turn on or off

analogous terms

• physiological psychology

• biological psychology

• biopsychology

• psychobiology

behavioral neuroscience

• behavioral phenomena that can be observed in humans and animals

• attempts to understand physiology of behavior

• behavior involves movement through muscles

reflexes

automatic, stereotyped movement that is produced as a direct results of a stimulus

who was Ramon-y-Cajal?

• used golgi stain to describe individual neurons

• 1906 nobel prize

discovered:

• 6 layers in the cortex

• complexity of nerve cells

• vertical organization

absolute size

human brain is small compared to other animals, but is considered a large brain

proportionliality

human brain makes up 2.3% of total body weight

connections

100 billion neurons each connect to about 10,000 other neurons generating a quadrillion connections

human characteristics that rely on a large brain

upright posture

tool use

fire

color vision

language

neoteny

slowing the process of maturation that allows more time for growth