History of Psychology: From Plato to Behaviorism & Cognitive Science

[00:00:06]If we are going to learn psychology, we actually  have to start with a little bit of history first.

[00:00:11]Now you may be wondering why a psychology  series is starting with a history lesson.

[00:00:16]Well, it turns out that what we  consider to be psychology today is very different than what was  considered to be psychology in the past.

[00:00:24]We will be focusing mainly on modern psychology in  this series, but knowing the history of psychology will give us a better understanding of  the influences that shaped psychology into the field of study that it is today. It  will also give us an idea of how psychologists both past and present think about the mind and how  it works. In knowing psychology’s history, we will be better prepared to understand and appreciate  the psychological concepts to be covered later.

[00:00:53]We’re going to start by going way back. People  have been thinking about the mind for thousands of years. Many cultures throughout history spent a  lot of time speculating on the nature of the mind and soul. The most prominent figures in ancient  psychology are Ancient Greek philosophers like Plato and his student Aristotle. They created  theories attempting to explain how the mind works and what causes human behavior. Plato, for  example, believed that the soul, or psyche, had three parts: the intellectual part, or logistikon;  the part that focused on wants and desires, or epithumetikon; and the emotional part,  or thumoeides. A healthy psyche would have all three parts in balance. Aristotle  built on Plato’s ideas about the mind, emphasizing observation and reason as the way  to acquire knowledge and understand nature.

[00:01:49]These ideas became the foundation of what we  consider early psychology today. The Greeks were so influential that we took their word for soul,  psyche, and made it part of the word psychology.

[00:02:04]Psychology continued to develop through the  Renaissance and was heavily influenced by the work of 17th century philosopher René Descartes.  Descartes believed that the mind and the body are two separate things. This is a theory  called Cartesian dualism or mind-body dualism.

[00:02:23]In dualism, the mind is an immaterial substance  that is the source of your thoughts, emotions, and beliefs, while the body is a physical substance.  The central claim of dualism is therefore that the immaterial mind and the material body are  two distinct substances which interact to cause behavior. But how can an immaterial thing interact  with a material thing? Descartes suggested that the immaterial soul resides in and influences the  body from the pineal gland, a part of the brain we learned about in our study of the endocrine  system. Philosophers continued to debate this idea and theorize other ways the mind could  work up until the middle of the 19th century.

[00:03:08]Now you may have noticed that we have  been using the term ‘philosopher’ instead of ‘psychologist’ when talking about  early psychology. When thinking about the mind, philosophers struggled with how to measure  immaterial things like thoughts and feelings.

[00:03:22]Since we couldn’t actually measure anything,  early psychology was considered to be a branch of philosophy and not a science. It wasn’t until  we started learning how the brain actually works that we could start using the scientific method  to study the mind. What we think of as psychology began in 1879 when German professor Wilhelm  Wundt founded the first experimental psychology lab at the University of Leipzig, officially  separating psychology from philosophy. In fact, Wundt was the first person ever to call himself a  psychologist. He and those in his lab began using the scientific method to study the mind, thereby  setting the stage for future psychologists.

[00:04:08]After Wundt, psychology grew into multiple schools  of thought and fields of study. The earliest school of thought is known as structuralism,  which was founded by Edward Titchener, a student of Wundt. Structuralists believed  that all psychological processes were made of basic elements, or structures. They discovered  these elements by asking research participants to describe their exact experiences as they work  on mental tasks, a process known as introspection.

[00:04:39]A person reading a book, for example, might say  that they are seeing some black lines on white paper. But structuralism was limited. Participants  often couldn’t accurately describe how they performed mental tasks. You’re seeing black  lines on paper when you read, but how do you get information from those lines? How do you describe  the manner in which you complete a math problem?

[00:05:03]From these questions, the structuralists realized  that the mind was doing things like processing information outside of our conscious awareness. This leads us to another school of thought called functionalism. Unlike the structuralists, the  functionalists believed that consciousness could not be broken down into parts. They believed it  was a continuous and changing mental process.

[00:05:29]Because of this view, the functionalists asked  a different question than the structuralists.

[00:05:34]Instead of trying to understand how the mind  works, functionalists wanted to know why the mind does certain things. Why do we have emotions? Why  do we form relationships? How do human behaviors help us live in our environment? Functionalists  tried to answer these questions by directly observing the human mind and human behavior. The neurologist Sigmund Freud created his own theory of psychology in the late 1800s and  early 1900s. He is the founding father of psychoanalysis, which focuses on the role of  unconscious thoughts, feelings, and memories in understanding behavior. Freud theorized  that these unconscious thoughts and forgotten memories controlled literally everything  that a person does. In Freudian psychology, the psyche is made up of three parts, much like  what Plato believed in Ancient Greece. To Freud, these three parts were the id, or instincts, the  ego, or reality, and the superego, or morality.

[00:06:41]So the id is the part of the psyche  that is full of primitive desires, sexual and aggressive drives, as well as  hidden memories, while the superego is the psyche’s moral conscience. The ego’s job  is to mediate between the other two parts.

[00:06:58]All three parts working together is  what ultimately creates human behavior.

[00:07:03]Unfortunately for Freud, the id, ego, and  superego are unobservable and cannot be tested scientifically, making this theory more philosophy  than psychology. Very few modern psychologists fully subscribe to Freudian principles any  longer, particularly his theory regarding psychosexual stages, but he was incredibly  influential in the development of psychoanalysis as well as the field of psychology itself, and we  will circle back to go deeper with Freud’s work later in the series. It was because of him that  psychologists began to study the unconscious mind, and how basic motivations and desires influence  behavior. Freud was also one of the first people to understand the importance of early childhood in  shaping adult behavior and personality, and one of the few people of his time to willingly discuss  pleasure and sexuality in a scientific context.

[00:07:57]Another school of thought arose in the early  20th century which was called behaviorism. Unlike other schools of thought, which focused  on the conscious and unconscious mind, behaviorism attempted to make psychology more  scientific by only studying observable behavior.

[00:08:15]One of the earliest behaviorists was Ivan  Pavlov, the physiologist who studied classical conditioning in dogs. This is something we  talked about while discussing learning and memory in the biopsychology series. As we recall,  he studied dogs who learned by repetition to associate a ringing bell with mealtime, and would  eventually salivate when they simply heard a bell, in anticipation of the associated meal. Pavlov  and other behaviorists thought that psychology was the study of behavior. Because you can’t  see or measure consciousness or the mind, you can’t use it as part of your scientific  study of psychology. The behaviorists were wrong about this, as we will discuss later.  One can indeed study thoughts and feelings.

[00:09:01]Although behaviorism isn’t a school of thought  any longer, it was important in establishing how learning occurs, and focusing on observable  behavior is an important part of psychology today.

[00:09:13]Starting in the 1960s, psychologists began to  wonder how the brain might be involved in mental processes like perception, thinking, memory, and  judgement. They still wanted to study observable behaviors like the behaviorists, but they wanted  to know what was going on inside the mind and the brain. This type of psychology, called cognitive  psychology, is an active area of research today.

[00:09:40]Cognitive psychologists study things like  perception, decision-making, and problem-solving, often using brain imaging tools like MRI to see  what role the brain plays in these behaviors.

[00:09:54]As we can see, psychology has changed  immensely from its early beginnings in philosophy with the Ancient Greeks, to the  start of experimental psychology in Wundt’s lab, and it continues to change and grow every year.

[00:10:08]Unlike psychologists of the past, today’s  psychologists do not necessarily identify with a particular school of thought like  functionalism, structuralism, or behaviorism.

[00:10:19]Modern psychologists instead typically have a  particular field of research that they focus on, like the cognitive psychologists we mentioned  before. Other fields include developmental psychology, which looks at how the mind changes  over a lifetime, and social psychology, which asks how social situations and cultures affect  our behavior. Each of these fields are huge and continuing to grow. In this series, we will talk  about a few main ideas from each of these fields to give you an idea of what kind of research is  occurring in psychology as a whole. For now, let’s move forward and talk about how psychologists  actually test what the mind is doing.