Relatively* durable or permanent change in what we do: behaviour, knowledge, capability, attitude. Acquired thru experience & not due to maturation, illness, injury. (infants don"t learn to walk) we don"t learn to walk psychologically, it"s developing stronger muscles. Conditioning learning by behavioural psychologists: classical conditioning. Also salivated to footsteps of assistants or rattling food dishes. Stimulus: any event or object in environment. Number of pairings of us & cs. Too much cake + pop + hotdogs + candy + chips at birthday party (us) sick (ur) Smell of drill (ns) no response. Smell of drill (cs) ouch (cr) Administration rituals counteract drug psychological tolerance. Different environment, no tolerance, more powerful effects & overdose more likely. Nausea-inducing drugs often prescribed to help people quit drugs, alcohol, other substances. Chanel n 5: ns no response. Chanel n 5: cs interest/envy (cr) Male rats, all had first mating experience wearing jackets . Half subsequently given sexual opportunities with jackets, half without.