Psychology – peter gray
1- Foundations for the study of
psychology
Introduction to psychology
Humans contemplate – we wonder how and why we do things. The scientific form
of contemplation is psychology.
Definition: psychology is the science of behavior and mind.
Behavior: observable actions of a person or animal.
Mind: individuals’s sensations, perceptions, memories, thoughts, dreams,
motives, emotions and other subjective experiences.
Mind is also: referring to all unconscious knowledge and operating rules that are
built into or stored in the brain and that provide the foundation for organizing
behavior and conscious experience.
Science: attempts to answer questions through systematic collection and
analysis of objectively observable data.
1879 – Wilhelm Wundt: the roots of psychology predate Wundt, but the founding
of psychology as sience happened when Wundt opened the first university based
lab and textbook.
Three fundamental ideas of psychology (before it was
recognized)
1. Behavior and mental experiences have physical causes that can be
studied scientifically
2. The way people behave, think, and feel is modified over time by their
experiences in their environment
3. The body’s machinery, which produced behavior and mental experiences,
is a product of evolution by natural selection
1. The idea of physical causation of behavior
The concept of "physical causation of behavior" developed through key
philosophical and scientific shifts. Descartes introduced the idea of the soul,
positing that the body operates mechanically but is influenced by the soul for
conscious thought and deliberate action. Despite this, his recognition of
mechanical processes in the body, such as reflexes, laid the groundwork for
understanding behavior as partly physical. Hobbes furthered this by rejecting the
soul entirely, arguing that all mental processes are purely physical. Together with
discoveries about reflexes and brain function localization, these ideas established
the foundation for modern psychology by demonstrating that behavior and
mental processes are rooted in physical brain activity.
Until the 18th century philosophy was constrained by religion.
,Dualism: a human being consists of a material body and immaterial soul.
The soul was a supernatural entity that operates on free will, not natural law, and
could not be studies scientifically – according to religion.
René Descartes (1596-1650): made an important step towards a scientific
analysis of human behavior with his version of dualism.
Descartes challenged the view that everything could be assigned to the soul
(body’s heat, ability to move etc.). He regarded the body as a machine, that is
capable of moving without influence of the soul. This resembles the modern
understanding of reflexes – involuntary responses to stimuli.
Nonhuman animals do not have souls.
The same behavior human and animals have can occur without the soul.
Thought: conscious deliberation and judgement. Humans have thought. Still
thought is responsive to sensory input.
Pineal body: the soul acts on the body at a particular physical location. Thread-
like structures (now nerves / neurons) bring sensory information to the soul, soul
thinks about it an triggers physical action by it’s wil.
Nerves /
External
neurons
sensory
information
Brain (pineal
Acts on muscles
body)
Nerves
Soul wills Soul thinks
movement about it
Limitations:
Philosophy: how can a nonmaterial entity (soul) have a material effect
(movement of the body). Also how can the body follow natural law, and yet be
moved by a soul which does not (Campbell, 1970).
Psychology: the theory limits what an be understood scientifically. The thought
and behavior guided by thought cannot be analyzed if they are product of a
willful soul.
Thomas Hobbes (1588-1679): and the philosophy of materialism – soul is a
meaningless concept. Nothing exists but matter and energy – materialism.
Conscious thought is a product of the brain’s machinery and subject to natural
law.
Therefore there are no limitations to what can be studied by psychologists. His
ideas helped inspire the school of thought about the mind known as empiricism.
Seeing the body and brain as a machine helped the study physiology, so that
discoveries were made about the nervous system that contributed to psychology.
Reflexes: one discovery especially important for the emergence of psychology
was an increased understanding of reflexes.
Descartes contributed to the idea that behavior can be mechanistic, while
Hobbes dismissed the soul entirely, viewing all mental processes as physical.
,Francois Magendie (1822): demonstrated that nerves entering the spinal cord
contain two separate pathways:
Carrying messages into the central nervous system from the skin’s sensory
receptors
Carrying messages out to operate muscles
Animals experiments showed the neural connections that underlie reflexes.
Reflexology: the view that all human behavior, including voluntary actions are
(complex) reflexes involving (higher) parts of the brain.
Sechenov: argues every human action can in theory be understood as a reflex.
All human actions are initiated by stimuli in the environment.
Sechenov inspired the work of Pavlov.
Localization of function in the brain: another important advance in the 19th
century physiology. Specific parts of the brain serve specific functions in the
production of mental experience and behavior.
Johannes Muller (1838/1965): proposed that the different qualities of sensory
experiences come about because the nerves of different sense organs excite
(prikkelen) different parts of the brain.
Pierre Flourens (1824/1965): damage to different parts of the brain causes
different kinds of deficit in animals’ ability to move.
Paul Broca (1861/1965): injury to the left side of the brain affects ability to speak,
but not other mental abilities.
The above gave substance to the idea of a material basis for mental processes
and thus helped lay groundwork for a science of psychology.
2. The idea that the mind an behavior are shaped by
experiences
The idea that "behavior is shaped by experience" stems from empiricism, which
holds that knowledge and thought come from sensory experiences. Locke viewed
the mind as a blank slate, where learning happens through environmental
interactions. The concept of association by contiguity—where experiences close
in time or space become linked—supports this view.
Conversely, nativism, as argued by Kant, posits that some knowledge is innate
and not acquired through experience. This ongoing debate between empiricism
and nativism reflects in modern psychology’s nature versus nurture discussion,
exploring the interplay between genetic predispositions and learned behaviors.
Empiricism: in this context knowledge and thought derive ultimately from
sensory experience. We are machines that learn.
Acquire Think Behave
Senses knowledge about the adaptively
about the world world
, Locke: a child’s mind is a blank slate. There is no disposition to make some types
of learning easier than others. There is no ‘human nature’ other than the ability
to adapt one’s behavior to the demands of the environment.
The empiricist concept of association by contiguity
Association by contiguity: contiguity refers to closeness in space or time. The law
of association by contiguity means that: if a person experience two
environmental events (stimuli) at the same time or one right after the other
(contiguity), those two events will become associated (bund together), such that
the thought of one event will in in the future tend to elicit the thought of the
other.
Word ‘apple’ can remind of it’s color, taste, sound.
This theory is still regarded as a fundamental principle of learning and memory.
Most of psychology was devoted to the study of the effects of people’s
environmental experiences on their thoughts, feelings and behavior.
The nativist response to empiricism
Nativism: opposite of empiricism. Most basic forms of human knowledge and
the basic operating characteristics of the mind, which provide the foundation for
human nature, are native to the human mind inborn, not acquired from
experience.
Kant (1724 – 1804):
A priori knowledge: built in to the human brain and does not have to be
learned.
Posteriori: gained from experience.
Without the first you cannot acquire the second.
Ability to learn a language a priori
Learning grammar and words posteriori
Today, the debate between empiricism and nativism is reflected in discussions
about the nature versus nurture debate, where modern psychologists explore the
balance between genetic predispositions and learned behaviors.
3. The idea that the machinery of behavior and mind evolved
through natural selection
Darwin's theory of evolution, as presented in "On the Origin of Species," provided
a biological basis for understanding behavior, proposing that traits enhancing
survival and reproduction are passed down through generations. Unlike
empiricists, who focused on how behavior relates to environmental experiences,
Darwin emphasized the evolutionary function of behavior—how it aids survival
and reproduction. This perspective integrates with earlier ideas by showing that
behavior is not just a result of experience but also shaped by evolutionary
pressures. Darwin's work reinforced the view that human behavior and
characteristics can be understood scientifically as part of the natural world.
Kant understood the mind has some innate furnishings, but did not understood
how or why they function as they do.
Charles Darwin (1809-1882): origin of species provide a biological grounding for
psychology.
