Declan lies on his back wanting his belly scratched.
The eight-year-old black Labrador cross swings his legs
in the air for a few minutes before resigning himself to
chewing on someone’s shoe.
In the office he behaves like any pet dog, but in the
field he is like a tornado—focused on finding illegal
drugs being smuggled. Declan is a drug-detector dog
for the Customs Service and has been busting drug
smugglers with his handler, Kevin Hattrill, for eight
Airport passengers look on with curiosity as Declan
darts around people and their luggage. Within minutes
he sniffs out a person of interest, who is taken away
and questioned by airport authorities.
Dogs like Declan are trained to detect illegal drugs,
such as cannabis, methamphetamine, and cocaine, or
explosives. Hattrill said the dogs were dual response-
trained when they detected something. “If the odor
is around a passenger, they are trained to sit beside
them. If it’s around cargo, they are trained to scratch.
When they detect something, their whole tempera-
ment will change.
“The dogs can screen up to 300 people within 10 to
15 minutes at the airport. Nothing else can do that.”
(McKenzie-McLean, 2006, p. 7)
A Four-Legged Co-Worker
Declan’s expertise did not just happen, of course. It is the result of painstaking training procedures—the
same ones that are at work in each of our lives, illustrated by our ability to read a book, drive a car, play
poker, study for a test, or perform any of the numerous activities that make up our daily routine. Like
Declan, each of us must acquire and then refine our skills and abilities through learning.
Learning is a fundamental topic for psychologists and plays a central role in almost every specialty
area of psychology. For example, a developmental psychologist might inquire, “How do babies learn to
distinguish their mothers from other people?” whereas a clinical psychologist might wonder, “Why do
some people learn to be afraid when they see a spider?”
Psychologists have approached the study of learning from several angles. Among the most fundamen-
tal are studies of the type of learning that is illustrated in responses ranging from a dog salivating when it
hears its owner opening a can of dog food to the emotions we feel when our national anthem is played.
Other theories consider how learning is a consequence of rewarding circumstances. Finally, several other
approaches focus on the cognitive aspects of learning, or the thought processes that underlie learning.
m o d u l e
The Basics of Classical Conditioning
±Applying±Conditioning±Principles to Human Behavior
The Basics of Operant Conditioning
±Positive±Reinforcers,±Negative Reinforcers, and Punishment
The Pros and Cons of Punishment: Why Reinforcement
Schedules of Reinforcement: Timing Life’s Rewards