by DK
"If the 19th century was the age of the editorial chair, ours is the century of the psychiatrist’s couch."
Marshall McLuhan
An influential science
The many branches of psychology that exist today cover the whole spectrum of mental life and human and animal behavior. The overall scope has extended to overlap with many other disciplines, including medicine, physiology, neuroscience, computer science, education, sociology, anthropology, and even politics, economics, and the law. Psychology has become perhaps the most diverse of sciences.
Psychology continues to influence and be influenced by the other sciences, especially in areas such as neuroscience and genetics. In particular, the nature versus nurture argument that dates back to Francis Galton’s ideas of the 1870s continues to this day; recently, evolutionary psychology has contributed to the debate by exploring psychological traits as innate and biological phenomena, which are subject to the laws of genetics and natural selection.
Psychology is a huge subject, and its findings concern every one of us. In one form or another it informs many decisions made in government, business and industry, advertising, and the mass media. It affects us as groups and as individuals, contributing as much to public debate about the ways our societies are or might be structured as it does to diagnosing and treating mental disorders.
The ideas and theories of psychologists have become part of our everyday culture, to the extent that many of their findings about behavior and mental processes are now viewed simply as “common sense.” However, while some of the ideas explored in psychology confirm our instinctive feelings, just as many make us think again; psychologists have often shocked and outraged the public when their findings have shaken conventional, long-standing beliefs.
In its short history, psychology has given us many ideas that have changed our ways of thinking, and that have also helped us to understand ourselves, other people, and the world we live in. It has questioned deeply held beliefs, unearthed unsettling truths, and provided startling insights and solutions to complex questions. Its increasing popularity as a university course is a sign not only of psychology’s relevance in the modern world, but also of the enjoyment and stimulation that can be had from exploring the richness and diversity of a subject that continues to examine the mysterious world of the human mind.
"The purpose of psychology is to give us a completely different idea of the things we know best."
Paul Valéry
INTRODUCTION
Many of the issues that are examined in modern psychology had been the subject of philosophical debate long before the development of science as we know it today. The very earliest philosophers of ancient Greece sought answers to questions about the world around us, and the way we think and behave. Since then we have wrestled with ideas of consciousness and self, mind and body, knowledge and perception, how to structure society, and how to live a “good life.”
The various branches of science evolved from philosophy, gaining momentum from the 16th century onwards, until finally exploding into a “scientific revolution,” which ushered in the Age of Reason in the 18th century. While these advances in scientific knowledge answered many of the questions about the world we live in, they were still not capable of explaining the workings of our minds. Science and technology did, however, provide models from which we could start asking the right questions, and begin to test theories through the collection of relevant data.
Separating mind and body
One of the key figures in the scientific revolution of the 17th century, the philosopher and mathematician René Descartes, outlined a distinction between mind and body that was to prove critical to the development of psychology. He claimed that all human beings have a dualistic existence—with a separate machinelike body and a non-material, thinking mind, or soul. Later psychological thinkers, among them Johann Friedrich Herbart, were to extend the machine analogy to include the brain as well, describing the processes of the mind as the working of the brain-machine.
The degree to which mind and body are separate became a topic for debate. Scientists wondered how much the mind is formed by physical factors, and how much is shaped by our environment. The “nature versus nurture” debate, fueled by British naturalist Charles Darwin’s evolutionary theory and taken up by Francis Galton, brought subjects such as free will, personality, development, and learning to the fore. These areas had not yet been fully described by philosophical inquiry, and were now ripe for scientific study. Meanwhile, the mysterious nature of the mind was popularized by the discovery of hypnosis, prompting more serious scientists to consider that there was more to the mental life than immediately apparent conscious thought. These scientists set out to examine the nature of the “unconscious,” and its influence on our thinking and behavior.
The birth of psychology
Against this background, the modern science of psychology emerged. In 1879, Wilhelm Wundt founded the very first laboratory of experimental psychology at Leipzig University in Germany, and departments of psychology also began to appear in universities across Europe and the US. Just as philosophy had taken on certain regional characteristics, psychology developed in distinct ways in the different centers: in Germany, psychologists such as Wundt, Hermann Ebbinghaus, and Emil Kraepelin took a strictly scientific and experimental approach to the subject; while in the US, William James and his followers at Harvard adopted a more theoretical and philosophical approach. Alongside these areas of study, an influential school of thought was growing in Paris around the work of neurologist Jean-Martin Charcot, who had used hypnosis on sufferers of hysteria. The school attracted psychologists such as Pierre Janet, whose ideas of the unconscious anticipated Freud’s psychoanalytic theories.
The final two decades of the 19th century saw a rapid rise in the importance of the new science of psychology, as well as the establishment of a scientific methodology for studying the mind, in much the same way that physiology and related disciplines studied the body. For the first time, the scientific method was applied to questions concerning perception, consciousness, memory, learning, and intelligence, and its practices of observation and experimentation produced a wealth of new theories.
Although these ideas often came from the introspective study of the mind by the researcher, or from highly subjective accounts by the subjects of their studies, the foundations were laid for the next generation of psychologists at the turn of the century to develop a truly objective study of mind and behavior, and to apply their own new theories to the treatment of mental disorders.
IN CONTEXT
APPROACH
Humorism
BEFORE
c.400 BCE Greek physician Hippocrates says that the qualities of the four elements are reflected in body fluids.
c.325 BCE Greek philosopher Aristotle names four sources of happiness: sensual (hedone), material (propraietari), ethical (ethikos), and logical (dialogike).
AFTER
1543 Anatomist Andreas Vesalius publishes On the Fabric of the Human Body in Italy. It illustrates Galen’s errors and he is accused of heresy.
1879 Wilhelm Wundt says that temperaments develop in different proportions along two axes: “changeability” and “emotionality.”
1947 In Dimensions of Personality, Hans Eysenck suggests personality is based on two dimensions.
The Roman philosopher and physician Claudius Galen formulated a concept of personality types based on the ancient Greek theory of humorism, which attempted to explain the workings of the human body.
The roots of humorism go back to Empedocles (c.495–435 BCE), a Greek philosopher who sugge
sted that different qualities of the four basic elements—earth (cold and dry), air (warm and wet), fire (warm and dry), and water (cold and wet)—could explain the existence of all known substances. Hippocrates (460–370 BCE), the “Father of Medicine,” developed a medical model based on these elements, attributing their qualities to four fluids within the body. These fluids were called “humors” (from the Latin umor, meaning body fluid).
Two hundred years later, Galen expanded the theory of humorism into one of personality; he saw a direct connection between the levels of the humors in the body and emotional and behavioral inclinations—or “temperaments.”
Galen’s four temperaments—sanguine, phlegmatic, choleric, and melancholic—are based on the balance of humors in the body. If one of the humors develops excessively, the corresponding personality type begins to dominate. A sanguine person has too much blood (sanguis in Latin) and is warm-hearted, cheerful, optimistic, and confident, but can be selfish. A phlegmatic person, suffering from excess phlegm (phlegmatikós in Greek), is quiet, kind, cool, rational, and consistent, but can be slow and shy. The choleric (from the Greek kholé, meaning bile) personality is fiery, suffering from excess yellow bile. Lastly, the melancholic (from the Greek melas kholé), who suffers from an excess of black bile, is recognized by poetic and artistic leanings, which are often also accompanied by sadness and fear.
Imbalance in the humors
According to Galen, some people are born predisposed to certain temperaments. However, since temperamental problems are caused by imbalances of the humors, he claimed they can be cured by diet and exercise. In more extreme cases, cures may include purging and blood-letting. For example, a person acting selfishly is overly sanguine, and has too much blood; this is remedied by cutting down on meat, or by making small cuts into the veins to release blood.
Galen’s doctrines dominated medicine until the Renaissance, when they began to decline in the light of better research. In 1543, the physician Andreas Vesalius (1514–1564), practicing in Italy, found more than 200 errors in Galen’s descriptions of anatomy, but although Galen’s medical ideas were discredited, he later influenced 20th-century psychologists. In 1947, Hans Eysenck concluded that temperament is biologically based, and noted that the two personality traits he identified—neuroticism and extraversion—echoed the ancient temperaments.
Although humorism is no longer part of psychology, Galen’s idea that many physical and mental illnesses are connected forms the basis of some modern therapies.
Imbalances in the humors determine personality type as well as inclinations toward certain illnesses.
GALEN
Claudius Galenus, better known as “Galen of Pergamon” (now Bergama in Turkey) was a Roman physician, surgeon, and philosopher. His father, Aelius Nicon, was a wealthy Greek architect who provided him with a good education and opportunities to travel. Galen settled in Rome and served emperors, including Marcus Aurelius, as principal physician. He learned about trauma care while treating professional gladiators, and wrote more than 500 books on medicine. He believed the best way to learn was through dissecting animals and studying anatomy. However, although Galen discovered the functions of many internal organs, he made mistakes because he assumed that the bodies of animals (such as monkeys and pigs) were exactly like those of humans. There is debate over the date of his death, but Galen was at least 70 when he died.
Key works
c.190 CE The Temperaments
c.190 CE The Natural Faculties
c.190 CE Three Treatises on the Nature of Science
See also: René Descartes • Gordon Allport • Hans J. Eysenck • Walter Mischel
IN CONTEXT
APPROACH
Mind/body dualism
BEFORE
4th century BCE Greek philosopher Plato claims that the body is from the material world, but the soul, or mind, is from the immortal world of ideas.
4th century BCE Greek philosopher Aristotle says that the soul and body are inseparable: the soul is the actuality of the body.
AFTER
1710 In A Treatise Concerning the Principles of Human Knowledge, Anglo-Irish philosopher George Berkeley claims that the body is merely the perception of the mind.
1904 In Does Consciousness Exist? William James asserts that consciousness is not a separate entity but a function of particular experiences.
The idea that the mind and body are separate and different dates back to Plato and the ancient Greeks, but it was the 17th-century philosopher René Descartes who first described in detail the mind-body relationship. Descartes wrote De Homine (“Man”), his first philosophical book, in 1633, in which he describes the dualism of mind and body: the non-material mind, or “soul,” Descartes says, is seated in the brain’s pineal gland doing the thinking, while the body is like a machine that operates by “animal spirits,” or fluids, flowing through the nervous system to cause movement. This idea had been popularized in the 2nd century by Galen, who attached it to his theory of the humors; but Descartes was the first to describe it in detail, and to emphasize the separation of mind and body. In a letter to the French philosopher Marin Mersenne, Descartes explains that the pineal gland is the “seat of thought,” and so must be the home of the soul, “because the one cannot be separated from the other.” This was important, because otherwise the soul would not be connected to any solid part of the body, he said, but only to the psychic spirits.
Descartes imagined the mind and body interacting through an awareness of the animal spirits that were said to flow through the body. The mind, or soul, residing in the pineal gland, located deep within the brain, was thought to sometimes become aware of the moving spirits, which then caused conscious sensation. In this way, the body could affect the mind. Likewise, the mind could affect the body by causing an outflow of animal spirits to a particular region of the body, initiating action.
"There is a great difference between mind and body."
René Descartes
Descartes illustrated the pineal gland, a single organ in the brain ideally placed to unite the sights and sounds of the two eyes and the two ears into one impression.
An analogy for the mind
Taking his inspiration from the French formal gardens of Versailles, with their hydraulic systems that supply water to the gardens and their elaborate fountains, Descartes describes the spirits of the body operating the nerves and muscles like the force of water, and “by this means to cause motion in all the parts.” The fountains were controlled by a fountaineer, and here Descartes found an analogy for the mind. He explained: “There is a reasoning soul in this machine; it has its principal site in the brain, where it is like the fountaineer who must be at the reservoir, whither all the pipes of the machine are extended, when he wishes to start, stop, or in some way alter their actions.”
While philosophers still argue as to whether the mind and brain are somehow different entities, most psychologists equate the mind with the workings of the brain. However, in practical terms, the distinction between mental and physical health is a complex one: the two being closely linked when mental stress is said to cause physical illness, or when chemical imbalances affect the brain.
RENÉ DESCARTES
René Descartes was born in La Haye en Touraine (now called Descartes), France. He contracted tuberculosis from his mother, who died a few days after he was born, and remained weak his entire life. From the age of eight, he was educated at the Jesuit college of La Flèche, Anjou, where he began the habit of spending each morning in bed, due to his poor health, doing “systematic meditation”—about philosophy, science, a
nd mathematics. From 1612 to 1628, he contemplated, traveled, and wrote. In 1649, he was invited to teach Queen Christina of Sweden, but her early-morning demands on his time, combined with a harsh climate, worsened his health; he died on February 11, 1650. Officially, the cause of death was pneumonia, but some historians believe that he was poisoned to stop the Protestant Christina converting to Catholicism.
Key works
1637 Discourse on the Method
1662 De Homine (written 1633)
1647 The Description of the Human Body
1649 The Passions of the Soul
See also: Galen • William James • Sigmund Freud
IN CONTEXT
APPROACH
Hypnosis
BEFORE
1027 Persian philosopher and physician Avicenna (Ibn Sina) writes about trances in The Book of Healing.
1779 German physician Franz Mesmer publishes A Memoir on the Discovery of Animal Magnetism.
AFTER
1843 Scottish surgeon James Braid coins the term “neuro-hypnotism” in Neurypnology.
1880s French psychologist Emile Coué discovers the placebo effect and publishes Self-Mastery Through Conscious Autosuggestion.