1.4 Perspectives in psychology

Philosopher Thomas Kuhn studied the history of science and found some remarkable convergences in the way schools of thought come and go and knowledge is generated. Kuhn (1970) observed that science does not progress, as many believe, primarily by accumulating ‘facts’. Rather, science progresses as much, or more, by developing better and better paradigms.

A paradigm is a broad system of theoretical assumptions that a scientific community uses to make sense of its domain of study. A paradigm has several components. First, it includes a set of theoretical assertions that provide a model, or an abstract picture, of the object of study. Chemists, for example, have models of the way atoms combine to form molecules — something the structuralists hoped to emulate by identifying basic ‘elements’ of consciousness and how they combined into thoughts and perceptions. Second, a paradigm includes a set of shared metaphors that compare the subject to something else that is readily apprehended (such as ‘the mind is like a computer’). Third, a paradigm includes a set of methods that scientists agree will produce valid and useful data. Astronomers, for example, agree that telescopic investigation provides a window to events in space.

According to Kuhn, the social sciences and psychology differ from the older natural sciences (such as physics and biology) because they lack an accepted paradigm upon which most members of the scientific community agree. Instead, he proposes, these young sciences are still splintered into several schools of thought, or what we will call perspectives.

The five perspectives that guide current psychological thinking, offer sometimes competing and sometimes complementary points of view. These perspectives offer the same kind of broad, orienting approach as a scientific paradigm, and they share its three essential features. Focusing on these perspectives does not mean that other less comprehensive approaches have not contributed to psychological knowledge or that nothing can be studied without them. These five perspectives generally guide psychological investigations and therapeutic interventions.

The psychodynamic perspective

In the late nineteenth century, Sigmund Freud (1856–1939), a Viennese physician, developed a theory of mental life and behaviour and an approach to treating psychological disorders known as psychoanalysis. Since then, many psychologists have continued Freud’s emphasis on psychodynamics, or the dynamic interplay of mental forces. The psychodynamic perspective rests on three key premises. First, people’s actions are determined by the way thoughts, feelings and wishes are connected in their minds. Second, many of these mental events occur outside of conscious awareness. And third, these mental processes may conflict with one another, leading to compromises among competing motives. Thus, people are unlikely to know precisely the chain of psychological events that leads to their conscious thoughts, intentions, feelings or behaviours.

As we will see, Freud and many of his followers failed to take seriously the importance of using scientific methods to test and refine their hypotheses. As a result, many psychodynamic concepts, such as ideas about unconscious processes, remained outside the mainstream of psychology until contemporary researchers brought them into the laboratory (Bargh & Morsella, 2008; Westen, 1998). In this text, we will emphasise those aspects of psychodynamic thinking for which the scientific evidence is strongest. You should recognise that researchers often interchange the terms psychoanalytic and psychodynamic, and psychologists in practice should consider the effectiveness of psychodynamic psychotherapies (Gaskin, 2014).

Origins of the psychodynamic perspective

Freud originated his theory in response to patients whose symptoms, although real, were not based on physiological malfunctioning. At the time, scientific thinking could not explain patients who were preoccupied with irrational guilt after the death of a parent or were so paralysed with fear that they could not leave their homes. Freud made a deceptively simple deduction that changed the face of intellectual history: if the symptoms were not consciously created and maintained, and had no physical basis, only one possibility remained — their basis must be unconscious.

Freud argued that just as people have conscious motives or wishes, they also have powerful unconscious motives that underlie their intentions. Many of us have had the infuriating experience of being stuck in a traffic jam on a highway, only to find nothing was blocking the road — just an accident in the opposite lane. Why do people slow down to gawk at accidents on the highway? Are they concerned? Perhaps. Freud would suggest that people feel an unconscious excitement, or at least satisfy a morbid curiosity, from viewing a gruesome scene, even though they may deny such socially unacceptable feelings.

Many have likened the relationship between conscious awareness and unconscious mental forces to the visible tip of an iceberg and the vast bulk that lies out of sight beneath the water. For example, an economics student went to see a psychologist because of a pattern of failing to hand in assignments. She would spend hours researching, write two-thirds of the assignment and then suddenly find herself unable to finish. She was perplexed by her own behaviour because she consciously wanted to succeed.

So, what lay beneath the surface? The patient came from a very traditional working-class family that expected girls to get married, not to develop a career. She had always outshone her brothers in school but hid her successes because of the discomfort this caused in the family. When she showed her report card, her mother would glance anxiously around to make sure her brothers did not see it. Eventually she learned to keep her grades to herself.

Years later, succeeding in a largely male course put her back in a familiar position, although she had not realised the link. The closer she came to success, the more difficulty she had finishing her assignments. She was caught in a conflict between her conscious desire to succeed and her unconscious association of discomfort with success. Research confirms that most psychological processes occur outside of awareness and that many of the associations between feelings and behaviours or situations that guide our behaviour are expressed implicitly or unconsciously (Combs et al., 2010; Westen, 1998).

Methods and data of the psychodynamic perspective

The methods psychodynamic psychologists use flow from their aims. Psychodynamic understanding seeks to interpret meanings — to infer underlying wishes, fears and patterns of thought from an individual’s conscious, verbalised thought and behaviour. Accordingly, a psychodynamic clinician observes a patient’s dreams, fantasies, posture and subtle behaviour towards the therapist. The psychodynamic perspective thus relies substantially on the case study method, which entails in-depth observation of a small number of people.

The most important legacy of the psychodynamic perspective is its emphasis on unconscious processes. The data of psychoanalysis can be thoughts, feelings and actions that occur anywhere, from a CEO jockeying for power in a corporate boardroom to a young child biting his brother for refusing to share a toy. Using any and all forms of information about a person reflects the psychodynamic assumption that people reveal themselves in everything they do.

According to Westen (1999, p. 1062), Freud contributed the following key propositions to psychoanalytic theory.

1. Enduring aspects of personality begin to emerge in childhood, and childhood experiences play an important role in personality development, shaping the ways people form later social relationships.

2. Mental representations of self, others, and relationships guide people’s interactions with others and play a substantial part in many forms of psychopathology.

3. Mental processes, including affective and motivational processes, operate simultaneously and in parallel, so that individuals can have conflicting feelings towards the same person or situation and can craft compromises outside of awareness.

4. Personality development involves not only learning to regulate sexual and aggressive feelings and wishes, but also moving from an immature dependent state to a mature independent one.

5. Much of mental life is unconscious.

Psychodynamic psychologists have typically relied primarily on clinical data to support their theories. Because clinical observations are open to many interpretations, many psychologists have been sceptical about psychodynamic ideas. A number of researchers, who are committed both to scientific method and psychodynamic concepts, have been subjecting psychodynamic ideas to experimental tests and trying to integrate them with the body of scientific knowledge in psychology (see Cohen et al., 2011; Westen & Gabbard, 1999). For example, several studies have documented that people who avoid conscious awareness of their negative feelings are at increased risk for a range of health problems such as asthma, heart disease and cancer (Andrew & Dulin, 2007; Singh & Mishra, 2011). Similarly, psychodynamic explanations have been offered and tested for their relevance to binge drinking (Blandt, 2002); attention-deficit hyperactivity disorder (ADHD; Rafalovich, 2001); and creativity (Esquivel, 2003).

More recently, a literature review of international and Australian research on the effectiveness of psychoanalysis and psychoanalytic psychotherapy suggests that positive long-term outcomes are evident for people with various conditions, including mood disorders, anxiety disorders, sexual dysfunction and personality disorders (Gaskin, 2014).

Research from the UK confirms these findings (British Psychoanalytic Council, 2017). Long-term psychoanalytic psychotherapy outcomes appear to be equivalent to those achieved via other psychotherapies and can be sustained after treatment (Gaskin, 2014). Gaskin (2014) further showed that short-term psychoanalytic psychotherapy is effective in treating depressive disorders. Gaskin’s review also supports the use of psychodynamic psychotherapy for generalised anxiety disorder, hypochondriasis and some personality disorders, including borderline personality disorder, among others. However, longer-term psychoanalytic psychotherapy of one year or more is more effective than shorter forms of therapy for treating complex mental disorders (British Psychoanalytic Council, 2017). Furthermore, evidence indicates that the long-term benefits of psychodynamic psychotherapy can be sustained over time, after treatment has terminated (Gaskin, 2014).

Criticisms of psychodynamic theory

Although elements of psychodynamic theory still play a huge role in psychology, no theory has been criticised more fervently. Criticisms have been so resounding that many question why the theory attracts any attention in textbooks and courses. Indeed, behaviourist John B. Watson referred to psychodynamic theory as ‘voodooism’. A lack of scientific grounding and empirical evidence for its key ideas, its violation of the falsifiability criterion, and its reliance on retrospective accounts are just a few of the criticisms aimed at psychodynamic theory. Nevertheless, there is no denying that Freud was a giant in the field and his provocative theories dramatically influenced the discipline of psychology (Dvorsky, 2013).

Psychodynamic theorists argue that its lack of reliance on empirical methods is one of its redeeming features. According to Fonagy (2003), in psychoanalysis ‘elusiveness and ambiguity are not only permissible, they may be critical to accurately depict the complexity of human experience’ (p. 74). Rather than investigating specific variables that reflect only a fraction of an individual’s personality or behaviour, psychodynamic theorists focus on the entire person (Westen, 1998) and the whole of human experience. In addition, by not relying on empirical methods, psychodynamic theorists study phenomena not amenable to more traditional experimental methods. For example, a psychodynamic theorist might study why certain people are drawn to horror stories and movies (Tavris & Wade, 2001). Westen, Novotny and Thompson-Brenner (2004) argue that research needs to make better use of randomised controlled clinical trials to test the efficacy of psychotherapies, and triangulate conclusions using data collected by other research methods, including clinical practice. Indeed, it has been proposed that advances in neuroimaging and other physiological measurements in clinical practice will see ‘the creation of a psychoanalysis that integrates biological and psychological principles into a unified theory of human mental life’ (Bornstein, 2005, p. 335).

The psychodynamic perspective proposes that people’s actions reflect the way thoughts, feelings and wishes are associated in their minds; that many of these processes are unconscious; and that mental processes can conflict with one another, leading to compromises among competing motives. Although their primary method has been the analysis of case studies, reflecting the goal of interpreting the meanings hypothesised to underlie people’s actions, psychodynamic psychologists are increasingly using experimental methods to integrate psychodynamic thinking with scientific psychology. This should alleviate the criticism that has traditionally been levelled against psychodynamic theorists for being non-empirical, violating the falsifiability criterion, and using unreliable measures and approaches.

The behaviourist perspective

Whereas the psychodynamic perspective emphasises internal mental events, behaviourism, also called the behaviourist (or behavioural) perspective, focuses on the way objects or events in the environment (stimuli) come to control behaviour through learning. Thus, the behaviourist perspective focuses on the relationship between external (environmental) events and observable behaviours. Indeed, John Watson (1878–1958), a pioneer of American behaviourism, considered mental events entirely outside the province of a scientific psychology, and B. F. Skinner (1904–1990), who developed behaviourism into a fully-fledged perspective years later, stated, ‘There is no place in a scientific analysis of behaviour for a mind or self’ (1990, p. 1209).

Origins of the behaviourist perspective

At the same time that Freud was developing psychoanalytic theory, Russian physiologist Ivan Pavlov (1849–1936) was conducting experiments on the digestive system of dogs. During these experiments, Pavlov made an important and quite accidental discovery. Once his dogs became accustomed to hearing a particular sound at mealtime, they began to automatically salivate whenever they heard it, much as they would if food was presented. The process that had shaped this new response was learning. Behaviourists argue that human and animal behaviours — from salivation in Pavlov’s laboratory to losing one’s appetite upon hearing the name of a restaurant associated with rejection — are largely acquired by learning. Indeed, psychologists have identified biochemical changes in brain cells and neural circuits involved in learning (Martinez & Derrick, 1996), often through the use of Pavlovian-type animal experiments. For example, researchers have demonstrated that injecting rats with a substance that activates glucocorticoid receptors — resulting in a natural biological stress response — enhances the rats’ memories of the affective components when they are learning responses to cues (Zorawski & Killcross, 2003). Research has also progressed to the point where interventions focused on neural and behavioural signals involved in re-learning old skills lost after a brain injury are now becoming possible (Kleim, 2011).

Behaviourists asserted that the behaviour of humans, like other animals, can be understood entirely without reference to internal states such as thoughts and feelings. They, therefore, attempted to counter Cartesian dualism (the doctrine of dual spheres of mind and body) by demonstrating that human conduct follows laws of behaviour, just as the law of gravity explains why things fall down instead of up.

The task for behaviourists was to discover how environmental events, or stimuli, control behaviour. John Locke (1632–1704), a seventeenth-century British philosopher, had contended that at birth, the mind is a tabula rasa, or blank slate, upon which experience writes itself. In a similar vein, John Watson later claimed that if he were given 12 healthy infants at birth, he could turn them into whatever he wanted, doctors or thieves, regardless of any innate dispositions or talents, simply by controlling their environments (Watson, 1925).

The environment and behaviour

Psychologist B. F. Skinner developed behaviourism as a fully-fledged perspective during the 20th century.

The dramatic progress of the natural sciences in the nineteenth century led many psychologists to believe that the time had come to wrest the study of human nature away from philosophers and put it into the hands of scientists. For behaviourists, psychology is the science of behaviour, and the proper procedure for conducting psychological research should be the same as for other sciences — rigorous application of the scientific method, particularly experimentation.

Scientists can directly observe a rat running through a maze, a baby sucking on a plastic nipple to make a mobile turn, and even the increase in a rat’s heart rate at the sound of a bell that has previously preceded a painful electric shock. However, no-one can directly observe unconscious motives. Science, behaviourists argued, entails making observations on a reliable and calibrated instrument that others can use to make precisely the same observations. If two observers can view the same data differently, as often occurs with psychodynamic inferences, how can a scientist test a hypothesis?

According to behaviourists, psychologists cannot even study conscious thoughts in a scientific way because no-one has access to them except the person reporting them. Structuralists such as Titchener had used introspection to understand the way conscious sensations, feelings and images fit together. But behaviourists such as Watson questioned the scientific value of this research, since the observations on which it relied could not be independently verified. They proposed an alternative to psychodynamic and introspective methods: study observable behaviours and environmental events and build a science around the way people and animals behave. Hence the term behaviourism. Today, many behaviourists acknowledge the existence of mental events but do not believe these events play a causal role in human affairs. Rather, from the behaviourist perspective, mental processes are by-products of environmental events.

Probably the most systematic behaviourist approach was developed by B. F. Skinner. Building on the work of earlier behaviourists, Skinner observed that the behaviour of organisms can be controlled by environmental consequences that either increase (reinforce) or decrease (punish) their likelihood of occurring. Subtle alterations in these conditions, such as the timing of an aversive consequence, can have dramatic effects on behaviour. Most dog owners can attest that swatting a dog with a rolled-up newspaper after it grabs a piece of steak from the dinner table can be very useful in suppressing the dog’s unwanted behaviour, but not if the punishment comes an hour later.

Behaviourist researchers have discovered that this kind of learning can help control some very unlikely behaviours in humans. For example, by giving people feedback on their biological or physiological processes (biofeedback), psychologists can help them to learn to control ‘behaviours’ such as headaches, chronic pain and blood pressure (Kapitza et al., 2010; Nestoriuc et al., 2008; Palomba et al., 2011).

Metaphors, methods and data of behaviourism

A primary metaphor of behaviourism is that humans and other animals are like machines. Just as pushing a button starts the coffee maker, presenting food triggered an automatic response in Pavlov’s dogs. Similarly, opening this text probably triggered the learned behaviour of underlining and note taking. Some behaviourists also view the mind as a ‘black box’ whose mechanisms can never be observed. A stimulus enters the box, and a response comes out; what happens inside is not the behaviourist’s business. Other behaviourists are interested in what might occur in that box but remain unconvinced that it is accessible to scientific investigation with current technologies. Consequently, they prefer to study what can be observed — the relationship between what goes in and what comes out.

The primary method of behaviourism is experimental. The experimental method entails framing a hypothesis, or prediction, about the way certain environmental events will affect behaviour and then creating a laboratory situation to test that hypothesis. Consider two rats placed in simple mazes shaped like the letter T, as shown in figure 1.2. The two mazes are identical in all respects but one: pellets of food lie at the end of the left arm of the first rat’s maze but not of the second. After a few trials (efforts at running through the maze), the rat that obtains the reward will be more likely to turn to the left and run the maze faster. The experimenter can now systematically modify the situation, again observing the results over several trials. What happens if the rat is rewarded only every third time? Every fourth time? Will it run faster or slower? Because these data can be measured quantitatively, experimenters can test the accuracy of their predictions, and they can apply them to practical questions, such as how an employer can maximise the rate at which employees produce a product.

Behaviourism was the dominant perspective in psychology, particularly in North America, from the 1920s to the 1960s. Pure behaviourism lost favour as psychology again became concerned with the study of mental processes. Many psychologists believe that thoughts about the environment are just as important in controlling behaviour as the environment itself (Bandura, 1977a, 1977b; Mischel & Shoda, 1995; Rotter, 1990). Some contemporary behaviourists even define behaviour broadly to include thoughts as private behaviours (see Calkin, 2002, for a review). Nevertheless, traditional behaviourist theory continues to have widespread applications, from helping people quit smoking to enhancing children’s learning in school.

Two contributions of the behaviourist perspective to psychology cannot be overestimated. The first is its focus on learning and its postulation of a mechanism for many kinds of learning: reward and punishment. Behaviourists offer a fundamental insight into the psychology of humans and other animals that can be summarised in a simple but remarkably important formula: behaviour follows its consequences. The notion that the consequences of our actions shape the way we behave has a long philosophical history, but the behaviourists were the first to develop a sophisticated, scientifically based set of principles that describe the way environmental events shape behaviour. The second major contribution of the behaviourist approach is its emphasis on empiricism — the belief that the path to scientific knowledge is systematic observation and, ideally, experimental observation.

The behaviourist perspective focuses on learning and studies the way environmental events control behaviour. Behaviourists reject the concept of ‘mind’, viewing mental events as the contents of a black box that cannot be known or studied scientifically. Scientific knowledge comes from using experimental methods to study the relationship between environmental events and behaviour.

The humanistic perspective

Humanistic theories focus on the uniqueness of the individual. Abraham Maslow (1908–1970) and Carl Rogers (1902–1987) are two key figures in humanistic psychology. They both emphasised self-actualisation — the idea that people are motivated to reach their full potential. The humanistic perspective represents an optimistic view of human experience. It assumes that people are innately good and will almost always choose adaptive, goal-directed and self-actualising behaviours.

Origins of the humanistic perspective

During the 1950s and especially the 1960s, an approach to personality emerged as an alternative to psychoanalysis and behaviourism. Unlike these approaches, humanistic approaches focus on aspects of personality that are distinctly human, not shared by other animals. How do people find meaning in life? How can they remain true to themselves amid lifelong pressures to accommodate other people’s wishes and preconceptions? Many humanistic psychologists argue that scientific methods borrowed from the natural sciences are inappropriate for studying people, whose actions, unlike those of fish or asteroids, reflect the way they understand and experience themselves and the world.

Metaphors, methods and data of the humanistic perspective

A humanistic metaphor is that life is like a bottle of milk — the cream always rises to the top. Imagine a young man growing up in a poverty-stricken home environment. He longs to study at university but does not have any financial support or resources to assist him. The young man enjoys studying and does well in school, despite the barriers his home environment presents. He longs to attend university to fulfil his lifelong dream of becoming a lawyer to help underprivileged children. Why will this man strive hard to realise his goals and ambitions? According to humanistic theory, he will do so to become a self-fulfilled individual and reach his full potential. He is driven by a desire to achieve all that he is capable of — it does not matter that he comes from a disadvantaged home environment.

The humanistic approach focuses on the individual’s unique perspective and experience. Humanistic theorists believe that people are not powerless victims of external forces but have an innate desire to improve themselves and fulfil their own potential. The goals people set for themselves are influenced by their own personal and subjective experiences. They can be chosen consciously as people strive to self-actualise. As a result, humanistic methods typically centre on helping individuals to understand their unique frame of reference and work towards achieving their desire to be the ‘best’ that they can be. The humanistic approach is very much person-centred and relies on the therapist showing empathy. The idea is to treat people with respect and warmth, stressing every individual’s freedom to make their own choices. Helping people to consciously and deliberately set self-actualisation goals modifies their behaviour.

The data of humanistic theory include the thoughts, motives and actions that reflect a person’s inner drive to realise their full potential. Humanists assume that people will act in ways that help them to achieve their life goals. They emphasise the central role of consciousness in shaping our behaviours, assuming that personal experience is a powerful medium for people to become more self-aware and self-directed.

The humanistic perspective emphasises the uniqueness of individuals and their potential for personal growth. Both Rogers (1959) and Maslow (1962) asserted that the prime motivator of all human behaviour is self-actualisation — an innate tendency that we have towards fulfilling our potential. According to this perspective, the way in which people perceive their own worlds determines their behaviour. Humanistic theorists believe that people experience problems when there is a discrepancy between their self-concept and the ideal self. This can occur when our expectations exceed our achievements. The humanistic approach readily lends itself to therapy because it focuses on the person’s immediate experience. However, some critics have viewed this perspective as naive because it assumes that people are basically ‘good’ and will grow if given the opportunity. The number of people in jails all around the world is one argument that people do not always act this way.

The humanistic perspective emphasises the uniqueness of the individual and focuses on the person’s immediate experience. Humanistic theorists assert that people have free will — the freedom to make choices so that they can fulfil their potential. According to this perspective, people are motivated to achieve personal goals so that they can fulfil their true potential.

The cognitive perspective

Psychology underwent a ‘cognitive revolution’ during the 1950s to 1960s. Today the study of cognition, or thought, dominates psychology in the same way that the study of behaviour dominated in the middle of the twentieth century. Indeed, the history of psychology could be viewed as a series of shifts:

from the ‘philosophy of the mind’ of the Western philosophers,

to the ‘science of the mind’ in the work of the structuralists,

to the ‘science of behaviour’ in the research of the behaviourists,

to the ‘science of behaviour and mental processes’ in contemporary, cognitively informed psychology.

The humanistic approach of the 1950s and 1960s was a shift away from the ‘science’ of psychology towards a focus on the unique experiences of each individual. The cognitive perspective focuses on the way people perceive, process and retrieve information. Cognitive psychology has roots in experiments conducted by Wundt and others in the late nineteenth century that examined phenomena such as the influence of attention on perception and the ability to remember lists of words. Gestalt psychology, too, was arguably a cognitive psychology, in its focus on the way people organise sensory information into meaningful units.

In large measure, though, the cognitive perspective owes its contemporary form to a technological development — the computer. Many cognitive psychologists use the metaphor of the computer to understand and model the way the mind works. From this perspective, thinking is information processing: the environment provides inputs, which are transformed, stored and retrieved using various mental ‘programs’, leading to specific response outputs. Just as the computer database of a bookstore codes its inventory according to topic, title, author and so on, human memory systems encode information in order to store and retrieve it. The coding systems we use affect how easily we can later access information.

To test hypotheses about memory, researchers need ways of measuring it. One way is simple: ask a question like, ‘Do you remember seeing this object?’ A second method is more indirect: see how quickly people can name an object they saw some time ago. Our memory system evolved to place frequently used and more recent information at the front of our memory ‘files’ so that we can get to it faster. This makes sense, since dusty old information is less likely to be relevant to our immediate environment. Thus, response time is a useful measure of memory.

The cognitive perspective is useful not only in examining memory but also in understanding processes such as decision making.

Origins of the cognitive perspective

The philosophical roots of the cognitive perspective lie in a series of questions about where knowledge comes from that the ancient Greek philosophers first raised and that British and European philosophers pondered during the last four centuries (see Gardner, 1985). Descartes, like Plato, reflected on the remarkable truths of arithmetic and geometry and noted that the purest and most useful abstractions — such as a hypotenuse, pi or a square root — could never be observed by the senses. Rather, the mind itself appeared to generate this kind of knowledge. Other philosophers, beginning with Aristotle, emphasised the role of experience in generating knowledge. Locke proposed that complex ideas arise from the mental manipulation of simple ideas and that these simple ideas are products of the senses, of observation.

The behaviourists roundly rejected Descartes’ view of an active, reasoning mind that can arrive at knowledge independently of experience. Cognitive psychologists, in contrast, are interested in many of the questions raised by Descartes and other rationalist philosophers, who emphasised the role of reason in creating knowledge.

Metaphors, methods and data of cognitive psychology

Both the cognitive and behaviourist perspectives view organisms as machines that respond to environmental input with predictable output. Some cognitive theories even propose that a stimulus evokes a series of mini-responses inside the head, much like the responses that behaviourists study outside the head (Anderson, 1983). However, most cognitive psychologists rely on different metaphors than their behaviourist colleagues. When the cognitive perspective emerged, perhaps what differentiated it most was that it filled the black box of the behaviourists with software — mental programs that produce output.

Many cognitive psychologists use the brain itself as a metaphor for the mind (e.g., Bassett & Gazzaniga, 2011). According to this view, an idea can be conceived as a network of brain cells that are activated together. Thus, whenever a person thinks of the concept ‘bird’, a certain set of nerve cells becomes active. Confronting a stimulus that resembles a bird activates part of the network; if enough of the network becomes active, the person concludes that the animal is a bird. A person is likely to recognise a sparrow as a bird quickly because it resembles most other birds and hence immediately activates most of the ‘bird’ network. Correctly classifying a penguin takes longer because it is less typically ‘birdlike’ and activates less of the network.

As with behaviourism, the primary method of the cognitive perspective is experimental, albeit with one important difference. Cognitive psychologists use experimental procedures to infer mental processes at work. For example, when people try to retrieve information from a list (such as the names of cities or towns), do they scan all the relevant information in memory until they hit the right item?

Cognitive psychologists primarily study processes such as memory and decision making. Cognitive research can also use cognitive concepts and metaphors to explain a much wider range of phenomena (Sorrentino & Higgins, 1996).

The cognitive perspective focuses on the way people perceive, process and retrieve information. Cognitive psychologists are interested in how memory works, how people solve problems and make decisions, and similar questions. The primary metaphor originally underlying the cognitive perspective was the mind as a computer. In recent years, many cognitive psychologists have turned to the brain itself as a source of metaphors. The primary method of the cognitive perspective is experimental.

The evolutionary perspective

•The impulse to eat in humans has a biological basis.

•The sexual impulse in humans has a biological basis.

•Caring for offspring has a biological basis.

•The fact that most males are interested in sex with females, and vice versa, has a biological basis.

•The higher incidence of aggressive behaviour in males than in females has a biological basis.

•The tendency to care more for one’s own offspring than for the offspring of other people has a biological basis.

Most people fully agree with the first of these statements, but have growing doubts as they move down the list. The degree to which inborn processes determine human behaviour is a classic issue in psychology called the nature–nurture controversy. Advocates of the ‘nurture’ position maintain that behaviour is primarily learned and not biologically ordained. Other psychologists, however, point to the similarities in behaviour between humans and other animals, from chimpanzees to birds, and argue that some behavioural similarities are so striking that they must reflect shared tendencies rooted in biology. Indeed, anyone who believes the sight of two male teenagers brawling behind the local high school for the attention of a popular girl is distinctively human should observe the behaviour of rams and baboons. Biological and genetic factors predispose people and other animals to certain physical and psychological experiences. It is the environment, however, that often determines the degree to which these predispositions actually manifest themselves.

The evolutionary perspective argues that many behavioural tendencies in humans, from the need to eat to concern for our children, evolved because they helped our ancestors survive and rear healthy children.

Like the functionalists at the turn of the century, evolutionary psychologists believe that most enduring human attributes at some time served a function for humans as biological organisms (Buss, 2000). They argue that this is as true for physical traits — such as the presence of two eyes (rather than one), which allows us to perceive depth and distance — as for cognitive and emotional tendencies such as a child’s distress over the absence of parents. The implication for psychological theory is that understanding human mental processes and behaviours requires insight into their evolution.

Origins of the evolutionary perspective

Charles Darwin revolutionised human self-understanding in 1859 by rewriting the family tree.

The evolutionary perspective is rooted in the writings of Charles Darwin (1859). Darwin did not invent the concept of evolution, but he was the first to propose a mechanism that could explain it — natural selection. Darwin argued that natural forces select traits in organisms that are adaptive and are likely to be passed on to their offspring. Adaptive traits are characteristics that help organisms to adjust and survive in their environment. Selection of organisms occurs ‘naturally’ because those not endowed with features that help them adapt to their particular environmental circumstances are less likely to survive and reproduce. In turn, they have fewer offspring to survive and reproduce.

Ethology, sociobiology and evolutionary psychology

In the middle of the twentieth century, the field of ethology, which studies animal behaviour from a biological and evolutionary perspective (Hinde, 1982), began to apply an evolutionary approach to understanding animal behaviour.

For example, several species of birds emit warning cries to alert their flock about approaching predators; some even band together to attack. Konrad Lorenz, an ethologist who befriended a flock of black jackdaws, was once attacked by the flock while carrying a wet black bathing suit. Convinced that the birds were not simply offended by the style, Lorenz hypothesised that jackdaws have an inborn, or innate, tendency to become distressed whenever they see a creature dangling a black object resembling a jackdaw, and they respond by attacking (Lorenz, 1979).

If animal behaviours can be explained by their adaptive advantage, can the same logic be applied to human behaviour? Harvard biologist E. O. Wilson (1975) christened a new and controversial field called sociobiology, which explores possible evolutionary and biological bases of human social behaviour. Sociobiologists and evolutionary psychologists, who apply evolutionary thinking to a wide range of psychological phenomena, propose that genetic transmission is not limited to physical traits such as height, body type or vulnerability to heart disease. Parents also pass onto their children behavioural and mental tendencies. Some of these are universal, such as the need to eat and sleep or the capacity to perceive certain wavelengths of light. Others differ across individuals.

Rsearch in behavioural genetics — a field that examines the genetic and environmental bases of differences among individuals on psychological traits — suggests that heredity is a surprisingly strong determinant of many personality traits and intellectual skills. The tendencies to be outgoing, aggressive or musically talented, for example, are all under partial genetic control (Loehlin, 1992).

Perhaps the fundamental concept in all contemporary evolutionary theories is that evolution selects organisms that maximise their reproductive success. Reproductive success refers to the capacity to survive and produce offspring. Over many generations, organisms with greater reproductive success will have many more descendants because they will survive and reproduce more than other organisms, including other members of their own species. Central to evolutionary psychology is the notion that the human brain, like the eye or the heart, has evolved through natural selection to solve certain problems associated with survival and reproduction, such as selecting mates, using language, competing for scarce resources and cooperating with kin and neighbours who might be helpful in the future (Tooby & Cosmides, 1992).

For example, we take for granted that people usually tend to care more about, and do more for, their children, parents and siblings than for their second cousins or non-relatives. Most of you have probably received more financial support from your parents in the last five years than from your aunts and uncles. This seems natural — and we rarely wonder about it — but why does it seem so natural? And what are the causes of this behavioural tendency?

From an evolutionary perspective, individuals who care for others who share their genes will have more of their genes in the gene pool generations later. And the genes involved in promoting that caring tendency in those individuals will be preferentially passed on as well. As a result, the caring trait (or predisposition for it) will also be passed on. Thus, evolutionary theorists have expanded the concept of reproductive success to encompass inclusive fitness, which refers not only to an individual’s own reproductive success but also their influence on the reproductive success of genetically related individuals (Hamilton, 1964).

According to the theory of inclusive fitness, natural selection favours animals whose concern for kin is proportional to their degree of biological relatedness. In other words, animals should devote more resources and offer more protection to close relatives than to more distant kin. The reasons for this preference are strictly mathematical. Imagine you are sailing with your brother or sister and with your cousin, and the ship capsizes. Neither your sibling nor your cousin can swim, and you can save only one of them. Who will you save?

Most readers (after a brief flicker of sibling rivalry) opt for the sibling because first-degree relatives share much more genetic material than more distant relatives such as cousins. Siblings share half of their genes, whereas cousins share only one-eighth. In crass evolutionary terms, two siblings are worth eight cousins. Evolution selects the neural mechanisms that make this preference feel natural — so natural that psychologists have rarely even thought to explain it.

At this point, you might object that the real reason for saving the sibling over the cousin is that you know the sibling better; you grew up together, and you have more bonds of affection. This poses no problem for the evolutionary theorist, since familiarity and bonds of affection are probably the psychological mechanisms selected by nature to help you in your choice. When human genes were evolving, close relatives typically lived together. People who were familiar and loved were, more often than not, relatives. Humans who protected others based on familiarity and affection would be more prevalent in the gene pool thousands of years later because more of their genes would be available. Thus, according to the evolutionary perspective, individuals are simply acting according to their genetic make-up and inherent tendencies.

Metaphors, methods and data of the evolutionary perspective

Darwin’s theory of natural selection is part of a tradition of Western thought since the Renaissance that emphasises individual self-interest and competition for scarce resources. Perhaps the major metaphor underlying the evolutionary perspective is borrowed from another member of that tradition, sixteenth-century philosopher Thomas Hobbes (1588–1679). According to Hobbes, wittingly or unwittingly, we are all in competition for survival, sexual access to partners, and resources for our kin and ourselves.

Evolutionary methods are frequently deductive; that is, they begin with an observation of something that already exists in nature and try to explain it with logical arguments. For instance, evolutionists might begin with the fact that people care for their kin and try to deduce an explanation. This method is very different from experimentation, in which investigators create circumstances in the laboratory and test the effect of changing these conditions on behaviour. Many psychologists have challenged the deductive methods of evolutionary psychologists, just as they criticise psychodynamic explanations of individual cases. They argue that predicting behaviour in the laboratory is much more difficult and therefore convincing than explaining what has already happened.

The evolutionary perspective asks basic questions about psychological processes that direct our attention to phenomena we might easily take for granted. Why do we think, feel or behave the way we do as opposed to some other way? The evolutionary perspective suggests a single and deceptively simple principle: we think, feel and behave in ways that helped our ancestors adapt to their environments, and hence to survive and reproduce.

The evolutionary perspective argues that many human behavioural tendencies evolved because they helped our ancestors to survive and reproduce. Psychological processes have evolved through the natural selection of traits that help organisms adapt to their environment. Evolution selects organisms that maximise their reproductive success, defined as the capacity to survive and reproduce as well as to maximise the reproductive success of genetically related individuals. Although the methods of evolutionary theorists have traditionally been deductive and comparative, evolutionary psychologists are increasingly using experimental methods.

•The psychodynamic perspective originates from the work of Sigmund Freud and argues that behaviour is largely the result of unconscious motives and early experiences. Psychoanalytic therapy involves inferring underlying wishes, motives and fears from an individual’s conscious, verbalised thought and behaviour.

•The behaviourist perspective originates from the early work of Pavlov and Skinner and focuses on learning — examining the way the environment shapes behaviour. Behaviour therapists advocate that experimental methods are needed to advance scientific understanding of human behaviour.

•The humanistic perspective represents an optimistic view of human behaviour and focuses on the uniqueness of the individual. Both Maslow and Rogers emphasised self-actualisation — the belief that people are motivated to reach their full potential. Humanistic therapists are person-centred, showing empathy to help individuals realise their potential for personal growth.

•Cognitive psychology focuses on the way people perceive, process and retrieve information. Descartes’ interest in the role of reasoning in creating knowledge prompted cognitive psychologists to examine how memory works and how people form abstract ideas, solve problems and make decisions.

•The evolutionary perspective stems from the work of Darwin and emphasises natural selection, whereby adaptive behavioural traits are passed through generations to help individuals adapt and survive in their environments.

The major perspectives have all made significant contributions to modern psychology. This explains why most contemporary psychologists do not adhere to one single intellectual perspective. Instead, a more integrative, unifying theme — the biopsychosocial model — has gained wide acceptance. This model views biological processes (genetics, neurotransmitters and evolution), psychological factors (learning, personality and motivation) and social forces (family, culture, gender and ethnicity) as interrelated. It sees all three factors as influences inseparable from the major perspectives.

Although the different perspectives offer radically different ways of approaching psychology, each has made distinctive contributions. These perspectives have often developed in mutual isolation, but efforts to integrate aspects of them are likely to continue to be fruitful, particularly in clinical psychology. The biopsychosocial model recognises that there is usually no single cause for our behaviour or our mental states. Rather, biological, psychological and social processes are seen as interrelated and interacting influences.