Behaviour and Response in Mammals
Senior 5 · Biology
Behaviour and Response in Mammals
Lesson 2 of 4
25 min
On a dairy farm in Gicumbi, the cows wander far across the pasture, but when the farmer rattles the feed bucket in the evening they come trotting to the shed. Calves born that season do not do this at first; they learn it within weeks. Learned behaviour changes with experience. It lets an animal adjust to its own particular surroundings, which inflexible innate behaviour cannot do. Psychologists and biologists recognise several kinds of learning, from the very simple to the very clever.
Definition
Learning: a lasting change in behaviour that results from experience.
Habituation: learning to stop responding to a repeated stimulus that is neither harmful nor rewarding.
Imprinting: rapid learning, during a short sensitive period early in life, to recognise and follow a particular object, normally the parent.
Classical conditioning: learning to give an existing response to a new stimulus that has been repeatedly paired with the original stimulus.
Operant conditioning (trial-and-error learning): learning to repeat an action that is followed by a reward, or to avoid one followed by an unpleasant result.
Touch the tentacles of a garden snail and it pulls them in. Touch it again and again, harmlessly, and it pulls them in for a shorter time each time, until it hardly responds. Birds that at first fly from a scarecrow soon ignore it; you stop noticing the sound of traffic or of a clock. Habituation saves energy and time for responses that matter. It is not tiredness: if a different stimulus is given, the full response returns at once.
In the 1930s the Austrian zoologist Konrad Lorenz showed that greylag goslings follow the first large moving object they see in the hours after hatching, and that goslings that first saw him followed him as if he were their mother. This learning happens only during a short sensitive (critical) period and is hard to reverse. In nature, it keeps the young close to the parent who protects and feeds them, and later helps them recognise a mate of their own species.
Worked example 1: habituation or fatigue?
Illustrative results: a snail's tentacle is touched gently every 30 seconds, and the time it stays withdrawn is recorded: 40 s, 28 s, 18 s, 10 s, 5 s, 2 s. Then its shell is tapped instead, and it withdraws for 38 s.
Around 1900, the Russian physiologist Ivan Pavlov was studying digestion in dogs. He noticed that his dogs began to salivate when they heard the assistant who fed them, before any food appeared. He then rang a bell just before giving food, many times. Eventually the bell alone made the dogs salivate (Figure 3).
The dog has linked a conditioned stimulus (the bell) with an unconditioned stimulus (food). If the bell is then rung many times without food, the conditioned response slowly fades: extinction. The cows that come to the rattling bucket show the same kind of learning.
In the 1930s, the American psychologist B. F. Skinner put rats in a box with a lever. While exploring, a rat pressed the lever by chance and a food pellet dropped out; soon it pressed the lever again and again. Behaviour followed by a reward is repeated (reinforcement); behaviour followed by something unpleasant becomes less frequent. Unlike classical conditioning, the animal learns to link its own action with a result. Farmers and trainers use it to teach oxen to plough or dogs to herd, by rewarding the right action.
Some learning is not shown until it is needed. In a famous study, Edward Tolman and Charles Honzik (1930) let rats explore a maze each day. Rats given food at the end every day made fewer and fewer mistakes. Rats never given food improved only slowly. A third group got food for the first time on day 11; next day they made almost as few errors as the group rewarded all along (Figure 4). They had been learning the maze all the time, without reward.
Between 1913 and 1917, the German psychologist Wolfgang Köhler hung bananas out of reach of chimpanzees in a large enclosure. After trying and failing, some chimpanzees paused, then stacked boxes or joined sticks together to reach the fruit, as if they had "seen" the solution. Insight learning solves a new problem by putting together past experiences, without trial and error. It is found mainly in animals with large brains: apes, some monkeys, crows and parrots, and humans.
| Type | What is learned | Example |
|---|---|---|
| Habituation | To ignore a harmless repeated stimulus | Birds ignore a scarecrow |
| Imprinting | To follow a parent, during a sensitive period | Goslings follow their mother |
| Classical conditioning | A new stimulus predicts an existing one | Dog salivates at a bell |
| Operant conditioning | An action leads to a reward or punishment | Rat presses a lever for food |
| Latent learning | Knowledge gained without reward, used later | Rats learn a maze while exploring |
| Insight learning | A new solution reasoned from past experience | Chimpanzee stacks boxes to reach fruit |
Worked example 2: reading the latent learning graph
Use Figure 4. (a) How many errors did group C make on days 11 and 12? (b) What does the sudden drop show? (c) Why is group B needed?
Warning
Common mistakes
FuseSchool: "Learned Behaviour". Watch for examples of habituation, imprinting, classical and operant conditioning and insight learning, and add one example of your own to each row of the table.
Tip
Memory hook: "Happy Infants Can Often Learn Ideas": Habituation, Imprinting, Classical, Operant, Latent, Insight, roughly from the simplest to the most complex.
Practice: learned behaviour
Key points
Sources and credits
Figures 3 and 4, the table, the worked examples and the practice questions are by Ganzaa. The results in Figure 4 and Worked example 1 are illustrative.
