Notes

Chapter Review
Psychology’s Roots: The Path to a Science of Mind
Psychologists use scientific methods to study mind and behaviour.
Early philosophers pondered and debated ideas about human nature, but could not provide empirical evidence to support their claims.
Some of the earliest successful efforts to develop a science linking mind and behaviour came from the French scientists Marie Jean Pierre Flourens and Paul Broca, who showed that damage to the brain can result in impairments of behaviour and mental functions.
Hermann von Helmholtz developed methods for measuring how long it takes a nerve impulse to travel to the brain, demonstrating that mental processes do not occur instantaneously.
Wilhelm Wundt is credited with the founding of psychology as a scientific discipline. He focused on analyzing the basic elements of consciousness, an approach that became known as structuralism.
William James applied Darwin’s theory of natural selection to the study of the mind. His functionalist approach focused on how mental processes enable people to adapt to their environments.
The Development of Clinical Psychology
After observing that some patients’ symptoms disappeared under a hypnotic state, psychologists began to focus on studying mental disruptions as a way of better understanding the human mind and behaviour.
Through his work with hysteric patients, Sigmund Freud developed psychoanalysis, which emphasized the importance of unconscious influences and childhood experiences in shaping thoughts, feelings, and behaviour.
Freud’s influence waned both because his dark view of human nature fell out of step with later, more optimistic times and because his ideas were difficult to test.
Humanistic psychologists offered a more positive view of the human condition, suggesting that people are inherently disposed toward growth and can usually reach their full potential with a little help from their friends.
The Search for Objective Measurement: Behaviourism Takes Centre Stage
Behaviourists advocated the study of observable actions and responses and held that inner mental processes were private events that could not be studied scientifically.
John B. Watson proposed that psychologists focus on what people do rather than on what they experience.
Working with dogs, Ivan Pavlov studied the association between a stimulus and a response and emphasized the importance of the environment in shaping behaviour. Watson believed the same techniques could be applied to human infants.
Influenced by Watson’s behaviourism, B. F. Skinner developed the concept of reinforcement, using a Skinner box. He demonstrated that animals and humans repeat behaviours that generate pleasant results and avoid performing those that generate unpleasant results.
Skinner extended Watson’s contentions about the importance of the environment in shaping behaviour by suggesting that free will is an illusion and that the principle of reinforcement can be used to benefit society.
Return of the Mind: Psychology Expands
Significant research on mental processes undercut behaviourism’s dominance.
– Gestalt psychology revealed that we perceive the whole rather than the sum of the parts.
– Memory studies revealed that what we recall is heavily influenced by our knowledge and beliefs.
– Jean Piaget studied the evolution of cognitive development in children.
– Kurt Lewin emphasized the importance of personal experience.
– The invention of the computer offered a useful model of the human mind.
– Psychologists’ efforts to improve the performance of the military revealed insight into the limitations of attention.
– Noam Chomsky’s theories about language showed that children have abilities that they have not been taught.
– Three Montrealers made foundational contributions to cognitive neuroscience by postulating the neural mechanism of memory (Donald Hebb), by discovering where certain kinds of long-term memories are stored in the brain (Brenda Milner), and by mapping function in the brain (Wilder Penfield).
Noninvasive brain scanning techniques made it possible for cognitive neuroscientists to observe the brain in action, furthering attempts to link psychology and physiology.
Evolutionary psychology focuses on the adaptive function that minds and brains serve and seeks to understand the nature and origin of psychological processes in terms of natural selection.
Beyond the Individual: Social and Cultural Perspectives
Triplett observed that the mere presence of others influences behaviour. Social psychology recognizes that people exist as part of a network of other people and examines how individuals influence and interact with each other.
Social psychology was pioneered by psychologists who desired to understand how people can influence each other to think and act in inhuman or irrational ways.
Cultural psychology is concerned with the effects of the broader culture on individuals and with similarities and differences among people in different cultures. Within this perspective, absolutists hold that culture has little impact on most psychological phenomena, whereas relativists believe that culture has a powerful effect. Together, social and cultural psychology help expand the discipline’s horizons beyond just an examination of individuals. These areas of psychology examine behaviour within the broader context of human interaction.
The Profession of Psychology: Past and Present
Several professional organizations support psychologists working in clinical, academic, and applied settings. The American Psychological Association (APA) and Canadian Psychological Association (CPA) represent clinical psychologists, while other organizations such as the Association for Psychological Science (APS) and Canadian Society for Brain, Behaviour and Cognitive Science (CSBBCS) support experimental psychologists.
Psychologists prepare for research careers through graduate and postdoctoral training and work in a variety of applied settings, including schools, clinics, and industry.
Research into the interconnectedness of scientific disciplines shows that psychology has a high impact on a variety of other areas.




Chapter Review
Empiricism: How to Know Stuff
Empiricism is the belief that the best way to understand the world is to observe it firsthand. It is only in the last few centuries that people have begun systematically collecting and evaluating evidence to test the accuracy of their beliefs about the world.
Observation doesn’t just mean “looking.” It requires a method. The scientific method involves (a) developing a theory that gives rise to a falsifiable hypothesis; and then (b) making observations that serve to test that hypothesis. Although these tests may prove that a theory is false, they can prove that it is true.
The methods of psychology are special because human beings are more complex, variable, and reactive than almost anything else that scientists study.
Observation: What Do People Do?
Measurement involves (a) defining a property in terms of a concrete, measurable condition, and then (b) using an instrument that can detect that condition. A good definition is valid (the concrete condition it measures is conceptually related to the property of interest), and a good instrument is both reliable (it produces the same measurement whenever it is used to measure the same thing) and powerful (it can detect the concrete conditions when they actually exist).
When people know they are being observed, they may behave as they think they should. Demand characteristics are features of a setting that suggest to people that they should behave in a particular way. Psychologists try to reduce or eliminate demand characteristics by observing participants in their natural habitats or by hiding their expectations from the participant. Observer bias is the tendency for observers to see what they expect to see or cause others to behave as they expect them to behave. Psychologists try to eliminate observer bias by making double-blind observations.
Psychologists often describe the measurements they make with a graphic representation called a frequency distribution, which often has a special shape known as the normal distribution. They also describe their measurements with descriptive statistics; the most common are descriptions of central tendency (such as the mean, median, and mode) and descriptions of variability (such as the range and the standard deviation).
Explanation: Why Do People Do What They Do?
To determine whether two variables are causally related, we must first determine whether they are related at all. This can be done by measuring each variable many times and then comparing the patterns of variation within each series of measurements. If the patterns covary, then the variables are correlated. Correlations allow us to predict the value of one variable from knowledge of the value of the other. The direction and strength of a correlation are measured by the correlation coefficient (r).
Even when we observe a correlation between two variables, we can’t conclude that they are causally related because there are an infinite number of third variables that might be causing them both. Experiments solve this third-variable problem by manipulating an independent variable, randomly assigning participants to the experimental and control groups that this manipulation creates, and measuring a dependent variable. These measurements are then compared across groups. If inferential statistics show that random assignment failed, then the results would only happen 5% of the time, then differences in the measurements across groups are assumed to have been caused by the manipulation.
An internally valid experiment establishes a causal relationship between variables as they were operationally defined and among the participants whom they included. When an experiment mimics the real world, it is externally valid. But most psychology experiments are not attempts to mimic the real world, but to test hypotheses derived from theories.
Thinking Critically About Evidence
Thinking critically about evidence is difficult because people have a natural tendency to see what they expect to see, to see what they want to see, and to consider what they see but not what they don’t.
Critical thinkers consider evidence that disconfirms their own opinions. They also consider the evidence that is absent, and not just the evidence that is present.
What makes science different from most other human enterprises is that science actively seeks to discover and remedy its own biases and errors.
The Ethics of Science: What’s Right?
Research Ethics Boards ensure that the rights of human beings who participate in scientific research are based on the principles of respect for persons, concern for welfare, and justice.
Psychologists are obligated to uphold these principles by getting informed consent from participants, not coercing participation, protecting participants from harm, weighing benefits against risks, avoiding deception, and keeping information confidential.
Psychologists are obligated to respect the rights of animals and treat them humanely. Most people are in favor of using animals in scientific research.
Psychologists are obligated to tell the truth about their studies, to share credit appropriately, and to grant others access to their data.