When in 1872 Charles Darwin published his book The Expression of the Emotions in Man and Animals, many people frowned: emotions in animals? Today scientists continue to explore the complex hidden world of animal behaviour, in which there are undoubtedly two pioneering figures who share the fact of having both died on February 27: Russian psychologist Ivan Petrovich Pavlov and Austrian zoologist Konrad Lorenz.
Curiously, it so happens that Pavlov (September 26, 1849 – February 27, 1936) and Lorenz (November 7, 1903 – February 27, 1989) not only did not defend the same ideas, but their theories largely differed. However, since they belonged to different generations and did not have the opportunity to discuss their views directly, in a sense one could say that they represent two successive stages in the construction of a science. And, in fact, Pavlov’s studies were for Lorenz the only thing worth saving from the tide that embraced the Russian’s work.
Pavlov’s experiments are well known. Dogs that salivate simply at the sound of the bell that announces their food are now part of popular culture. However, when all is said and done, it is by no means clear that the researcher actually employed a bell, but rather used metronomes and buzzers. Less well known, however, is that this was an accidental discovery, since Pavlov’s intention was not really to study behaviour, but rather digestion.
In 1884, with his doctorate in physiology in his pocket, Pavlov began researching the digestive function in dogs. The animals salivated when offered food, but while studying this, the physiologist made a curious observation: once dogs had learned to identify their minders, they would salivate just by looking at them.
Thus, he soon discovered that animals could associate a neutral stimulus, such as a sound, with an unconditioned stimulus, food, so that the former became a conditioned stimulus capable of provoking the same response as food. Pavlov called this response “psychic secretions” that were produced as a “conditional reflex” (today’s conditioned reflex). In 1904, Pavlov received the Nobel Prize in Physiology or Medicine for his research on the digestive glands. But one year earlier he had presented at a medical congress in Madrid the work on what is now called classical conditioning, which really made him a famous figure for posterity.
Around the same time, a new school of psychology was being born in the United States: behaviourism. Behaviourists rejected a psychology that could not be measured or predicted. For this reason, they developed a systematic methodology that allowed them to take the study of behaviour to the laboratory, through controlled conditions and observable responses. For the behaviourists, behaviour was learning from environmental stimuli; the mind at birth was a blank slate, without innate patterns. When behaviourists learned about Pavlov’s work, they welcomed it as a revelation, although disagreements would soon arise.
Lorenz and animal Instincts
In the 1930s, with behaviourism on the rise, an Austrian zoologist who studied animal instincts thought that laboratory experiments were too reductionist to understand behaviour; when behaviourists put pigeons in opaque boxes to study an isolated response, he said, it was because they were afraid that animals might do other things that would weaken their simplistic theories. Lorenz is today known above all for his studies on imprinting, the linking of chicks to the first large moving object they see; but his vision of behaviour as complex learning about a set of innate patterns, where reflexes are one more element, elevated him as one of the fathers of ethology, the biology of animal behaviour.
But just as Lorenz’s attitude towards the behaviourists derived from his refusal to engage with the acrimonious dispute, he was instead respectful of Pavlov’s ideas; he appreciated his physiological approach to behaviour, something that did not interest the behaviourists. The ethologist thought that the Russian’s experiments revealed much more than he had concluded, and that those conclusions supported his own theory. “I am far from laughing at Pavlov,” he once wrote. Sixty-nine years after Pavlov, Lorenz would also have his name inscribed on the list of Nobel Prize winners.