Leo Kanner was influenced, I suggest, primarily by two concepts, Kraepelin’s taxonomy of mental disorders and Freudian psychodynamics. But before moving on to Kanner’s landmark paper, I want to take a look at the thinking behind Kraepelin’s classification and Freud’s ideas.
Beliefs about the causes of human behaviour changed a great deal during the 19th century. At the beginning of the 1800s, the long-held idea that human beings had two independent spheres of existence – the spiritual and the physical – was being widely questioned. By the end of the 1800s, another idea was in doubt – this time the separate existence of the mind and the brain. I suggest this challenge came about largely because of two fields of research; the study of brain pathology and Darwin’s work on natural selection.
Brain pathology: the brain-behaviour connection
During the 19th century knowledge about the anatomy and function of the brain increased significantly, mainly because of the study of brain damage. Armed conflict and poor working conditions were commonplace in Europe and the US, so there was no shortage of brain-damaged patients for researchers to observe. Famous case studies were published involving personality changes (Phineas Gage) or specific cognitive impairments (Dejerine’s Monsieur C.). By the end of the century, the link between brain damage – from accidents or stroke – and abnormal behaviour was well established. Finding the cause of abnormal behaviour in people who appeared to have no sign of physical damage proved more challenging.
A German psychiatrist called Emil Kraepelin decided to tackle this problem. The chances of finding the causes of somatic disorders (disorders of the body) had improved by applying a simple principle of diagnosis; that the same signs and symptoms in different patients were very likely to have the same cause. If the causes of mental disorders (disorders of the mind) such as delusions, dementia and abnormal behaviour actually originated in an organ of the body, the brain, the same principle of diagnosis could be applied to them. A complication was that the symptoms of different somatic disorders sometimes overlap, so Kraepelin proposed that mental disorders should be identified by their unique pattern of symptoms and by how those patterns changed over time.
From 1887 onwards Kraepelin developed a classification of mental disorders in successive editions of his Textbook of Psychiatry. He concluded that mental disorders could be grouped into two main types; dementia praecox (in which the patient’s condition deteriorated) and manic depressive illness (in which episodes of illness were interspersed by periods of good health). Although classifications of mental disorders have changed a great deal since then, Kraepelin’s system forms the foundation for the Diagnostic and Statistical Manual of Mental Disorders (DSM) and the International Classification of Diseases: Mental and Behavioural Disorders (ICD) used today.
Emil Kraepelin had been born in Neustrelitz, Germany in February 1856. Three months later, 800 km away in what is now Příbor in the Czech Republic, another figure who had a significant influence on the way mental disorders were understood came into the world – Sigmund Freud. (Interestingly, Freud’s parents, like Leo Kanner’s, were Galician Jews.) Eighteen years later, both Freud and Kraepelin were studying medicine – Freud in Vienna and Kraepelin in Leipzig.
The influence of Darwin
When Kraepelin and Freud were three years old, Charles Darwin published his major work On the Origin of Species. What Darwin proposed was that an individual organism’s inherited characteristics determine how well it survives in a given environment. If the organism survives long enough to reproduce, its characteristics will be passed on to its offspring. Over time the characteristics of a particular species will change, the changes reflecting environmental conditions. Given a sufficient length of time completely new species could develop. Darwin’s ideas are an important component of Freud’s concept of psychodynamics.
Freud had graduated in 1881 and began work as a neurologist with Theodor Meynert in Vienna. In 1885 he had the opportunity to study under Jean-Martin Charcot, the famous French neurologist. This was a turning point for Freud. Charcot’s use of hypnosis to treat hysteria triggered Freud’s interest in mental disorders and led to his development of psychodynamic theory.
A fundamental concept in psychodynamics is that of instinctive drives such as the desires for food, social interaction and sex, that shape behaviour. With Meynert Freud had studied brain anatomy, and believed that instinctive drives originated in the brain. Like other biological characteristics, drives are passed on to subsequent generations via sexual reproduction. Natural selection acts in favour of drives that increase the likelihood of successful reproduction, resulting over time in species-specific patterns of instinctive behaviour. Freud suggested that the normal development of these patterns can be disrupted by early experiences such as a parent withholding food or affection, or imposing religious or cultural taboos on a child. Because of the importance of sexual reproduction in one generation passing on drives to the next, social and sexual behaviours are a very important part of the psychodynamic framework.
Kraepelin’s taxonomy and Freud’s psychodynamics influenced Leo Kanner partly because of Adolf Meyer, Kanner’s boss at Johns Hopkins Hospital. Meyer, ten years younger than Kraepelin and Freud, had qualified as a neuropathologist in Zurich. Because of problems getting a secure post, he had emigrated to the US in 1892, where he became a highly influential figure, becoming director of the Psychiatric Institute in New York, professor of Psychiatry at Cornell, director of the first inpatient psychiatric unit in the US at Johns Hopkins hospital and president of the American Psychiatric Association. Whilst at John Hopkins he put Kanner in charge of the first academic child psychiatric department and the clinic where Kanner first saw patients with childhood autism.
Bentall, R. (2004). Madness Explained: Psychosis and Human Nature, Penguin.
A radical appraisal of the way psychotic illnesses are classified.
Gardner, H. (1977). The Shattered Mind: The Person After Brain Damage, Routledge & Kegan Paul.
A fascinating account of Gardner’s experience working with brain-damaged patients and the history of brain-damage research. And yes, it is the Howard Gardner who wrote Multiple Intelligences.
Again, much of the biographical material came from Wikipedia. For a summary see Hall of Fame.