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Writer's Profile
Olivia Lyle

Specialised Subjects

Biology, Criminology, Health, Neuroscience, Philosophy, Quantitative Methods, Statistics

I have a first class Honour’s degree in Psychology and my research interest is predominantly in behavioural neuroscience, particularly with how certain drugs affect the brain and behaviour. I am a critical thinker and highly adept at evaluating information as I can easily determine how theories/research relate to my arguments. I am also very experienced at searching literature databases; this proves to be very useful in gaining a broad yet detailed and current understanding of the issues in question. I am a member of the British Psychological Society and ensure that I keep abreast of new fields of psychological research. I would like to get back into research and take advantage of the  PhD opportunities that are available.

Psychology as a science – Is Psychology a Science and Should it be?

To address the question posed, an evaluative review of the historical development of psychology, its current state and the direction it appears to be taking in conjunction with its coherence with science will be the main focus of this essay. The second part of the question, whether psychology should be regarded as a science, will be reflected upon throughout the essay; the answer is most likely dependent on psychology’s current status and the several fundamental philosophical issues which pervade this discipline. Firstly, it is important to define psychology and science. These are elusive concepts, primarily because they are the products of history. As the two disciplines have morphed over time, so has their definition. Accordingly, if I am to arrive at a legitimate conclusion regarding psychology’s scientific status, logic dictates that this must be based on a valid, up-to-date definition. The British Psychological Society, the representative body for psychology and psychologists in the UK, states that psychology is ’the scientific study of people, the mind, and behaviour (BPS, 2007). Other definitions include the ’scientific study of behaviour and mental processes’ (Atkinson et al., 1993), and ‘a word variously defined as the study of the mind, behaviour, or man interacting with his social and physical environment’ (Allan et al., 1998). Several of these definitions intimate that psychology is the scientific study of a variety of phenomena, thus implying that psychology is a science. However, the definition of science must be considered to determine the legitimacy of this hypothesis. During science’s history, empiricism, logical positivism and Karl Popper have all played pivotal roles in defining what science is now. (Gross,1992). The integration of these perspectives has produced a set of comprehensive criteria which include: a definable subject matter, hypothesis testing, theory construction, facts to be established by empirical methods and not rational argument, and, finally, the attempt to discover general laws or principles that govern human behaviour, applicable to every member of the human species (Gross, 1992). This definition can be sub-divided into scientific theory and method. Karl Popper’s (1963) introduction of falsifiability led to the demarcation of  science from pseudo-science; ’a theory which is not refutable by any conceivable event is non-scientific’.  Currently, a good theory is characterised by not only falsifiability, but with how it deals with the objective truth. Further characteristics are whether it is comprehensive, how it explains the past and predicts future events with reference to laws, whether it is internally consistent, has heuristic value, and, finally, has empirical support (Gross, 1992). So we have recognised the hallmark of a ‘good’ scientific theory, but what of its method? Scientists utilise the empirical method which aims at establishing the ‘objective truth’, studying phenomena in their purest form (physical matter), being unbiased and value free, and conducting research with maximum control, that is, in laboratory settings (Valentine, 1992). If the psychologist employs scientific assumptions at both the theoretical and methodological level, it is more than likely that psychology would be considered to be a reputable science. However in view of the scientific criteria outlined, the validity of this hypothesis can only be tested by the review of both confirmatory and falsifying evidence regarding the current and future state of psychology and its coherence with science. Literature of this nature will be considered throughout the course of this essay.

The factors that make a ‘good’ science have been reviewed; it has been postulated that a definable subject matter is one of the first principles (Gross, 1992). Based on the heterogeneity of definitions previously outlined (BPS, 2007; Atkinson et al., 1993; Allan et al., 1998) psychology’s subject matter is far from defined. Accordingly, if there is a lack of clarity regarding the subject matter under examination, it will be reflected at higher levels; that is, psychological theory, methods and perspectives. Support for this claim is provided by Kuhn’s theory of scientific progression (1962). Kuhn (1962) states that science proceeds according to an historical cycle of ‘normal science’ and ‘revolutions’. In essence, a ‘paradigm’ emerges, which governs the subject of observation and generates theories, methods of study, and the application of such theories (Masterman, 1970). A revolution occurs when a build-up of conflicting evidence becomes so overwhelming that there is a crisis; the old paradigm is abandoned and a new paradigm takes over. This model of science is consistent with psychology’s progression over time. From the time that psychology was first recognised as a specific field, there have been several major paradigm shifts; structuralism in the 1880s was succeeded by behaviourism in the 1930s. In the early 1960s, a cognitive revolution occurred (Gross, 1992; Eysenck & Keane, 2000), resulting in a change in theoretical and methodical assumptions that had been, historically, part of psychology. In view of this, it can plausibly be argued that because psychology has followed a similar historical pattern to science, it is a science. However there is a further convolution to this argument. These paradigm shifts indicate that, in its entirety, psychology lacks internal consistency, perhaps the direct result of its vague definition, which contradicts the scientific criteria. So is psychology scientific? If psychology is not a unified subject but an umbrella term which covers a multitude of competing old and new perspectives, then each paradigm or perspective must be considered with reference to its theory, methods, and application to clarify whether these schools of thought are coherent with scientific criteria, and hence establish if psychology, in general, is a science. This is the main aim of this essay.

In view of the fact that the behaviourist and cognitive paradigms have dominated psychology in the last 70 years, these will be the primary focus of this essay with other paradigms receiving less attention Firstly, behaviourism will be considered. The single stage stimulus-response (S-R) theory is central to this paradigm; that is, responses are predicted as a function of the stimulus (Valentine, 1992). Only the observable behaviour is considered worthy of study; anything irrelevant is ignored (Watson, 1913). Such theoretical assumptions posited the use of animals such as rats and mice in highly controlled laboratory experiments, or typical conditioning paradigms. The fear response has been the focus of much recent research, and in accordance with S-R theory, Le Doux (1994) has found that fear can be predicted by the type of stimulus used. To elaborate, rodents can learn to exhibit fear in response to a non-threatening stimulus (tone) if it is consistently paired and associated with a threatening stimulus (mild shock to the foot) (Le Doux, 1994). This is known as classical conditioning (Pavlov, 1927). From this research, it could be proposed that behaviourism is both theoretically and methodologically consistent with science: it employs the scientific method in that experiments are unbiased, value free and conducted with maximum control, behavioural hypotheses are falsifiable, there is clear empirical support for classical conditioning theory, and finally, the subject matter, (behaviour), is definable. Because this paradigm is consistent with science, psychology may implicitly also be regarded as a science. Behaviourist theory is deterministic; that is, it can predict future behaviour. Because actions are bound by S-R laws, the question of people having free choice is raised. It would seem that when actions are the result of conditioning this could be considered to be the same as having no control (Bem & de Jong, 2006). This line of argument has implications for sex offender behaviour and the issue of moral responsibility. If it can be asserted that sex offenders have no free will or control over their actions, then they cannot be held morally responsible for their behaviour (Webel & Sigliano, 2004). However, current psychological theories suggest that the aetiology of sexually deviant behaviour incorporates biological and developmental factors which occur within a socio-cultural context that fails to discourage sexual abuse (Marshall & Serran, 2000). This implies some degree of control; behaviour cannot be simplistically evaluated, nor can actions be predicted on the basis of the function of a specific stimulus. This point is supported by the Heisenberg uncertainty principle (as cited in Valentine, 1992); indeterminism exists at the level of sub-atomic physics. Therefore, if there is unpredictability at the lower physical level, there is likely to be some degree of unpredictability, and accordingly, control, at the higher behavioural level. The ramifications of this are that sexual offenders are morally responsible for their behaviour; they are not simply reacting to S-R conditioning. Perhaps psychology needs to extend its reach beyond the study of behaviour, and focus on the subjective, psychological dimension of sexual deviancy. Define the mind! This is the direction which psychology ultimately took, as evidenced throughout the course of this essay.

As well as acknowledging that psychology needed to extend beyond the objective, behaviourism inadvertently sparked psychology’s progression into the biological domain. For example, Le Doux’s (1994) research intimated the existence of an acoustic (tone) – somatosensory (pain) interface within the brain. Information regarding these two forms of stimuli, when communicated, result in a fear response. Direct findings such as these were not ignored; they had the potential to facilitate an understanding of human behaviour. However if ‘pure’ behaviourists attempted to ascertain the location of this interface, they would be highly criticised for extending their focus too far beyond their defined subject matter, that is, behaviour. The upshot of this was that psychology expanded in synchrony with the type of research findings it obtained. Psychology made the only logical manoeuvre; adoption of the biological perspective. This was an excellent move if psychology was to secure its status as a science, for reasons which I shall outline later. The central tenet underlying the biological perspective is that behaviour, actions and experiences can all be related to physiology and genetics (Kalat, 2004). To focus more on neurobiology (the brain) however, it has been proposed that a putative link may exist between human anxiety disorders and the brain systems underlying the defence reaction in animals (Blanchard et al., 1998; 2001). Empirical research supports the findings that the amygdala plays a major role in mediating fear and anxiety in rhesus monkeys (Amaral, 2002), and this is substantiated by human research (Ohman & Mineka, 2001). When considering psychology as a science, the neurobiological perspective is the most consistent of all the  perspectives, for reasons previously outlined when discussing behaviourism perspective. It studies neurobiology in its purest form. Moreover, psychology’s inadvertent adoption of reductionism, which postulates that mental states can be explained in terms of a neural mechanism (Valentine, 1992), enhanced psychology’s standing as a science. To be more specific, reductionism leads to unification of and increased systematicity between theories within a perspective. As previously documented, these are the hallmarks of good scientific theory; thus it follows that the adoption of internally consistent perspectives will promote psychology’s demarcation from pseudo-science. However this adoption of reductionism was not necessarily  beneficial for two reasons:

Firstly, it is currently considered to be a popular perspective, that of social psychology. This perspective restricts its focus to what can be observed, that is, social behaviour (Hogg & Vaughan, 2002). The central premise of social psychology is that the presence of other people can affect individual behaviour (Hogg & Vaughan, 2002). An example of this is deindividuation theory; individuals can lose awareness of their individual identity in a crowd, resulting in uncontrolled, disinhibited behaviour (Le Bon, 1895). This theory has been successfully applied to ‘football hooliganism’, and other forms of riotous behaviour, each attributable to the loss of a sense of ‘self’ (Stott et al., 2001; Reicher, 1984; Reicher, 1996a). However the ‘individualistic’ account provides an alternative social explanation; riotous crowd behaviour may be the result of a gathering of individuals who share commonalities in terms of character and disposition; that is, violent, criminal and anti-social personalities (Allport, 1924; Stott et al., 2001). This highlights the limitations of reductionism; the dispositional account decontextualises the crowd and removes any meaning from its action (Reicher, 1996b). However both explanations, individual and group, are equally credible. The implications for psychology, if reductionism is ‘the bread and butter of science’ (Bem & de Jong (2006), are clearly that it should not become a science if it wants to fully rationalize behaviour. It must consider a number of explanations and reject reductionism. However with respect to science, social psychology’s principals are not entirely coherent. Firstly, it employs qualitative methods. For example, Stott et al. (2001) conducted an ethnographic study in which data underwent triangulation; that is, both quantitative and qualitative methods were used. Secondly, because social psychologists are ultimately studying themselves, they cannot achieve the level of objectivity necessary for a scientific study of social behaviour. For these reasons, social psychology could be deemed pseudo-scientific, which, hence, brings psychology’s status as a science into disrepute. It can be concluded that, social psychologists are unique in that they adhere to some scientific principles and methods but in fact oppose reductionism. This is, perhaps, the direction psychology is currently taking; an integration of pseudo-scientific and scientific principles and methods.

Secondly, a prerequisite for reduction is the ordering of sciences from higher to lower levels; for example, sociology, psychology, physiology, chemistry and physics respectively (Valentine, 1992). The concept of derivability states that higher level sciences, such as psychology, can deduce laws from lower level sciences, such as physiology, as evidenced by Ohman & Mineka’s (2001) research, but not vice versa (Valentine, 1992). However a further condition of reductionism, termed definability is that there must be a bridging law between the mental and the physiological (Valentine, 1992). The question to be answered is: how do the psychological (anxiety) and neurobiological (amygdala) aspects relate? This represents what is known as the mind-body problem. There are numerous points of view on this issue. Dualism is the belief that the mind and body are different kinds of substance that somehow interact (McGhee, 2001). However neurobiologists reject this view because dualism conflicts with the physicist’s law of conservation of matter and energy: the only way to accelerate matter or transform energy in your body is to act upon it with other matter or energy (as cited in Kalat, 2004). Based on this, the mind, if its function can be affected by neurobiology, must be material. This provides support for the monist view; the belief that the universe consists of only one kind of substance; that is, if the body is material then the mind must be too. In effect, anxiety is a dysfunction of the amygdala (Valentine, 1992). This is consistent with the proposal that pain might be identical with the firing of C-fibres (Bem & de Jong, 2006). However, perhaps monist views are a little extreme; the mere existence of some of the terms used in folk psychology, such as the mind, suggests these conceptualisations must have some utility. An elegant solution is provided by Siegel (1999), who promotes the emergent view. The mind is the product of the brain.  It is not a separate or parallel feature; it is something which grows out of but remains fundamentally rooted to a physical system (McGhee, 2001). The implications for psychology are that if the psychological is the emergent product of the physical, then it follows that psychology’s focus should be restricted to biological perspectives to understand the aetiology of psychological concepts such as the mind. This, in turn, would result in the inevitable classification of psychology as a science attributable to biological psychology’s high degree of coherence with scientific theory and methods. Therefore, the future of psychology as a science will, in part, depend on the psychologists’ philosophical stance to the mind-body problem. This in turn, however, suggests that the validity of psychology as a science is highly questionable if the perspectives which will dominate in the future are dependent on a philosophical stance. Psychology may fare better as a science if it didn’t try to explain problems beyond its scope; its roots may be philosophical but if it  is going to be defined as a science, it must reject these roots and all that is related.

To summarise, psychology’s adoption of the biological perspective could be considered a logical progression from behaviourism. The two perspectives complement one another; behaviourism’s discovery that the fear response could be learned facilitated the identification of the neurobiological basis of fear. However both approaches are reductionist and fail to clearly define the relationship between the mind and body. Physiology is focused upon the body which in effect rejects the sole aim of psychology; the scientific study of mental phenomena and an understanding of the psychological, anxious states (reflected by social psychological theory). In view of this, it is appropriate to make reference to Freud, a true advocate of anti-reductionism; the whole is greater than the sum of its parts (Valentine, 1992). Although his theories are relatively mature, they are not obsolete, and his methods are still used clinically. (Atkinson et al., 1992). Freudian perspectives thus have some bearing on psychology’s current and future status as a science.

Freud’s theory of mind states that thoughts, ideas, memories and other psychic material can operate at one of three levels: the conscious, pre-conscious and unconscious (as cited in Freud, 1976). Freud believed that much of human behaviour had multiple causes, some conscious, and some unconscious. If we are only aware of the conscious causes for our actions, we assume these are the reasons for our actions. However, if the causes of our actions also include unconscious factors, then the reasons we give for our behaviour may not be fully explanatory (Gross, 1992). Thus, based on Freudian theory, it is vital that the unconscious is studied for a further understanding of the mind.
Freud developed psychoanalysis, which involved the interpretation of dreams, neurotic symptoms, and parapraxis to explore the unconscious. Psychoanalysis was used to alleviate what Freud termed ‘hysterical conversion neurosis’, whereby mental illness (anxiety) is transformed into physical illness (paralysis, blindness, headaches) (as cited in Freud, 1976). However, with respect to science, Freud can be criticised for many reasons: his methods are neither unbiased nor value-free, and the mind is not a definable subject matter; it is a fragmented construct. A psychologist cannot confirm the existence of the unconscious; it can only be inferred. Freud’s theory, because it cannot be tested, can never gain empirical support and acceptance as a scientific theory. If psychology advocates a pseudo-scientific perspective, it is unlikely to ever attain a reputation of being a science.

Nevertheless, Freudian theory provides a different explanation of anxiety and the mind-body problem to the neurobiological and behaviouristic perspectives. Freud believes mental processes do exist and are not non-causal by-products of physical dysfunction (as cited in Freud, 1976). This view supports dualism and interactionism, from the point of view that the mind governs the body (Valentine, 1992). If this reverse form of interaction is possible, clearly a psychological level of explanation is required which extends beyond the physiological (Fodor, 1981). This only strengthens social psychology’s arguments that psychology should not move towards the biological even if this means that it forfeits its status as a science. Such a move would limit its capability as a discipline to understand the mind and behaviour. This line of argument is substantiated in view of the subject of consciousness.  Biological psychology and behaviourism can be criticised for the use of animal subjects. Freudian theory proposes that humans have three levels of consciousness. Bem & de Jong (2006) basing their theory on the inferred existence of these internal constructs, postulate that the human mind is different from that of the animal. Humans also possess the attributes of intentionality and intelligence. This begs the question, how can the defensive behaviour of an animal possibly reflect human anxiety? Human anxiety has a psychological dimension (APA, 2000); an individual’s private, subjective, personal experience of anxious thoughts and feelings. If psychology adopts the reductionist behavioural and neurobiological methods, it cannot hope to provide an explanation of a higher level construct; that of human emotion. Conscious, subjective experience can only be measured by means of qualitative methods, such as those which Freud promotes. Although these methods lack scientific status, they do measure the desired construct, the consciousness. Therefore, if psychology is a higher level science, which is concerned with explaining higher level concepts, it is entirely appropriate for it to use, and continue to use, what can be deemed to be higher level methods.

Based on the perspectives so far reviewed, it would seem that psychology is at a crossroads. It needs to ask whether scientific status is more significant than the understanding of the human mind and mental processes. The answer to this question lies in the direction psychology took in the early 1960s. There was a high degree of discontent with the behaviourist approach due to its promotion of reductionism and determinism and failure to resolve the mind-body problem. There was a crisis in psychology (Valentine, 1992). Cognitivism developed and the focus extended beyond that of the directly observable (Eysenck & Keane, 2000). The cognitive psychologist opposed the notion that behaviour could be predicted on the basis of a stimulus alone. Instead, increasing weight was given to the study of internal mediating processes; the mind or ‘black box’. This directly contradicted scientific principles and methods (Valentine, 1992). By the end of the 1970s, the computational theory of the mind was the central tenet in psychology. This theory maintains that individuals interact with the external world via the mind. The mind is a processing system which transforms symbols into different symbols, relating to objects in the external world (Eysenck & Keane, 2000). The models of face recognition represent examples of the theory of the mind (Bruce & Young, 1986; Burton & Bruce, 1993). These models assert that familiar and unfamiliar faces are processed by two separate cognitive systems. The existence of two processing systems accounts for the finding that the identification of familiar faces is generally very good, but not that of unfamiliar faces (Hancock, Bruce & Burton, 2000). This explains the findings of Schleck and colleagues (2000)  that out of 100 people who were wrongly convicted, as later proved by DNA evidence, 75% of these were convicted on the basis of false eye witness testimony. These findings also highlight the inconsistent nature of the mind. The implications of this are that if the mind is not a definable, infallible subject matter, it cannot be scientifically studied. If this is the case, then the methods, theories and perspectives used to explain it, must be pseudo-scientific. Support for this argument comes from the fact that cognitive face processing theories lack falsifiability. It is impossible to confirm or refute whether constructs such as face recognition units and person identity nodes exist in the mind (Bruce & Young, 1986). Furthermore, while cognitive psychology performs experiments in controlled laboratory settings, it challenges scientific principles by the indirect measurement of the mind. Inferences are made about internal cognitive processes based on subjects’ behaviour, such as measures of speed and accuracy. Based on these arguments, it seems that cognitive psychology is more of a pseudo-science than a science. Nonetheless, a key strength of the cognitive perspective is that it provides an innovative account of the mind-body problem beyond the philosophical perspectives so far reviewed. The relationship between the software (programmed instructions about operations) and the hardware (the chips and processors by which those instructions are performed) provides a metaphor for the relationship between thinking and the brain (McGhee, 2001). Furthermore the law of conservation of matter and energy can be reconciled. Computer programmes simulate human thinking and other higher-level processing tasks; hence it is easy to explain how mental processes can arise from physical entities based on cognitive theory (McGhee, 2001). Although cognitive psychology can ultimately be deemed to be a pseudo-science, unlike neurobiology and Freudian theory, it does not rely on philosophical arguments to explain how the mind and body interact, which adds weight to the argument that it is, in part, scientific.

To conclude, several psychological perspectives have been reviewed, to give a legitimate response to whether psychology is a science. Psychology has a colourful history. It began as a pseudo-science when Wunditian and Freudian perspectives were reputable; from here it was moulded into a science via Watson and the promotion of behaviourism, and then reverted back to its pseudo-scientific status when it adopted social and cognitive psychology, which still remain. I contend that, in its current state, psychology is a pseudo-science (see Fig. 1). I have argued that two of the current dominant perspectives (social and cognitive) in psychology are not scientific. This brings its standing as a science into disrepute. One piece of falsifying evidence can condemn an entire scientific theory. (Popper, 1963). However, this is not necessarily always the case in psychology; for example, the monoamine theory of depression (McNeal & Cimbolic) has been repeatedly falsified and yet is still upheld. This point further indicates psychology’s pseudo-scientific status; theology supersedes science. Theological principals state that even if a theory is proved wrong, based on scientific principles, it is still defended by the intensity with which it is believed (Valentine, 1992). The primary focus of psychology is the study of the mind; through the current dominant paradigm, cognitivism. Even if the mind is studied using the scientific method, because it is not definable and can only be inferred, psychology can never classify itself as science. Even the claim that psychology is a pseudo-science can only be asserted with some degree of certainty, primarily because an hypothesis is much easier to refute than to prove. This is the key limitation of the scientific method. It is not surprising that psychology can be regarded as pseudo-scientific, but this change in direction may have been facilitative. In particular, the cognitive psychologists’ resolution of the mind-body problem was a milestone in psychology’s short history, revolutionising the conceptualisation of the human mind.

In its current form, psychology represents a composite discipline, as reflected by Fig. 1. Its rejection of reductionism, has led to the existence of several levels of explanation, some compatible, and some incompatible with science, each however with excellent explanatory power. This is reflected in the study of aggression. Aggression has a heterogeneous nature, it is neither parsimonious, nor simplistic and hence it is not easy to study (Martin Ramirez, 2000; Geen, 2001). Aggressive behaviour may be the result of a neurobiological dysfunction (Renfrew, 1997; Diaz, 1995), an instinct (Archer, 1995), a drive (Berkowitz, 1990), learning (Renfrew, 1997), physical abuse experienced as a child (Geen, 1990), or even socio-cultural influences (Renfrew, 1997). If psychology were to become a strict science and a unified discipline, the aetiology of acts like aggression could never be fully understood. Two individuals could commit the same act of aggression in terms of objective analysis, but the aetiology of the act may in reality be very different (Barratt & Slaughter, 1998). The implications of these research findings is that psychology should remain pseudo-scientific; it is an integrative discipline with a diverse subject matter. Although psychology may be divided in terms of its theoretical and methodological assumptions, it is a unified by its overarching and primary objective, the attempt to understand the mind, mental processes and behaviour.

Figure 1

FIG 1: Hierarchical model of perspectives to demonstrate psychology’s current overall status as a pseudo-science. Red= dominant paradigms and perspectives in psychology in the last 20 years.

In view of the arguments presented, it is entirely justifiable to assert that, in its present state, psychology is not a science and moreover it should not endeavour to be. It is psychology’s success at understanding mental phenomena which is paramount, not its classification as a science. It has been successful in terms of the former; as for the latter, its chance of becoming a science is limited. The best outlook for psychology’s future therefore, will be to attain success within its field, and not attempt to be scientific. A final point to consider is that only some psychological perspectives have been presented in this discursive essay. They were selected, firstly, because these perspectives have received much attention and hence represented major dictators of psychology’s status as a science, and, secondly, because these perspectives are still relatively popular to date, both academically and in terms of their clinical application, thus permitting conceivable speculations to be made about the future state of psychology. Consideration of other psychological perspectives (abnormal, developmental) may cast further light on psychology’s status as a science and its future directions. However, in view of recent technological advances, it can be assumed that the neurobiological perspective will dominate psychology’s future. The use of neuro-imaging techniques, MRIs, EEGs and PET scans enables the psychologist to test the relationship between neuro-anatomical structures and behaviour and effect a true integration of the physiological and the psychological. Thus, technological advances will govern psychology’s scientific progression. So perhaps psychology’s future as a pseudo-science is not set in stone.

References.

Allan, B., Stallybrass, O.B. & Trombley, B., (1998), The Fontana Dictionary of Modern Thought (2nd ed.), London: Fontana Press., pp 698-700.

Allport, F.H., (1924), Social Psychology. Boston: Houghton Mifflin Company.

Amaral (2002), Amygdala and rhesus monkeys.

American Psychiatric Association, (2000), Diagnostic and Statistical Manual of Mental Disorders–IV: DSM-IV-TR. Washington, D.C. pp 429- 484.

Archer, J., (1995),  What can ethology offer the psychological study of human aggression, Aggressive Behaviour, 21. 243- 255.

Atkinson, R.L., Atkinson, R.C., Smith, E.E. & Bem, D.J. (1993), Introduction to Psychology (11th ed.). Philadelphia: Harcourt Brace Jovanovich Inc. pp 2-31.

Barratt & Slaughter (1998). Human aggression.

Bem, S., & de Jong, H.B., (2006), Theoretical Issues in Psychology: An Introduction (2nd ed.), London: Sage Publications.

Berkowitz, L., (1990), On the formation and regulation of anger and aggression: A cognitive neo-associationistic analysis, American Psychologist. 45. 494- 503.

Blanchard, D.C., Griebel, G., Rodgers, R.J. & Blanchard, R.J., (1998), Benzodiazepine and serotonergic modulation of antipredator and conspecific defense, Neuroscience & Biobehavioural Reviews. 22. 597-612.

Blanchard, D.C., Hynd, A.L., Minke, K.A., Minemoto, T. & Blanchard, R.J. (2001), Human defensive behaviours to threat scenarios show parallels to fear- and anxiety-related defence patterns of non-human mammals, Neuroscience & Biobehavioural Reviews. 25. 761-770.

British Psychological Society. (2007). Website.

Bruce, V. & Young, A.W., (1986), Understanding face recognition, British Journal of Psychology. 77. 305- 327.

Burton, A.M. & Bruce, V., (1993), Naming faces and naming names: Exploring an interactive activation model of person recognition, Memory. 1. 457- 480.

Diaz, G., (1995), Traumatic brain injury and criminal behaviour, Medicine and Law, 14. 131- 140.

Eysenck, M.W. & Keane, M.T., (2000), Cognitive Psychology: A student’s handbook, New York: Psychology Press, 1-23.

Fodor, J.A., (1981), Representations: philosophical essays on the foundations of cognitive science. Cambridge, MA: MIT Press.

Freud, S., (1976), The psychopathology of everyday life, Harmondsworth, Middlesex: Penguin. (Original work published 1901).

Geen, R.G., (1990), Human Aggression, Milton Keynes: Open University Press.

Gross, R.D., (1992), Psychology: The science of mind and behaviour (2nd ed.), London: Hodder & Stoughton Educational.

Hancock, P.J.B., Bruce, V. & Burton, A.M., (2000), Recognition of unfamiliar faces. Trends in Cognitive Science, 4. 330- 337.

Hogg, M.A. & Vaughan, G.M., (2002), Social Psychology (3rd ed.), London: Pearson Prentice Hall.

Le Bon, G., (1895, trans. 1947), The Crowd: A study of the popular mind, London: Ernest Benn.

Le Doux, J.E., (1994), Emotion, memory and the brain, Scientific American, June 1994. 32- 39.

Kalat, J.W., (2004), Biological Psychology (8th ed.), London: Thomson Wadsworth.

Kuhn, T.S, (1962), The structure of scientific revolutions, Chicago: University of Chicago Press.

Masterman, M., (1970), The nature of the paradigm, In: I. Lakatos & A. Musgrave (eds.), Criticism and the Growth of Knowledge, Cambridge: Cambridge University Press, 59-89.

Martin Ramirez, J., (2000), Animal models in the research of human aggression, Aggression and Violent Behaviour, 5, 281- 290.

McGhee, P., (2001), Thinking Psychologically, Basingstoke: Palgrove.

McNeal & Cimbolic.

Noble, D., (1990), Biological explanation and intentional behaviour, In: K.A. Mohyeldin Said, W.H. Newton-Smith, R. Viale & K.V. Wilkes (eds.). Modelling the Mind. Oxford: Clarendon Press, 97- 112.

Ohman, A. & Mineka, S., (2001), Fears, phobias and preparedness: toward an evolved module of fear and fear learning, Psychological Review, 108, 483- 522.

Patel, S. & Hillard, C.J, (2006), Pharmacological evaluation of cannabinoid receptor ligands in a mouse model of anxiety: further evidence for an anxiolytic role for endogenous cannabinoid signalling, Journal of Pharmacology and Experimental Therapeutics, 318. 304- 311.

Pavlov, I.P., (1927), Conditioned reflexes, London: Oxford University Press.

Popper, K.J., (1963), Conjectures and Refutations: The growth of scientific knowledge, London: Routledge & Kegan Paul Ltd., 33- 65.

Reicher, S.D., (1984), The St. Paul’s riot: An explanation of the limits of crowd action in terms of a social identity model, European Journal of Social Psychology. 14, 1-21.

Reicher, S.D., (1996a), ‘The Battle of Westminster’: Developing the social identity model of crowd behaviour in order to explain the initiation and development of collective conflict, European Journal of Social Psychology, 26, 115- 134.

Reicher, S.D., (1996b), Social identity and social change: Rethinking the contexts of social psychology, In: P.W. Robinson (ed.), Social groups and identities: Developing the legacy of Henri Tajfel,  Oxford: Butterworth Heinemann, 317- 336.

Renfrew, J.W., (1997), Aggression and its Causes: A Biopsychosocial approach, Oxford: Oxford University Press.

Schleck et al. (2000). EWT.

Siegel, D.J. (1999). In webel.

Stott, C., Hutchison, P. & Drury, J., (2001), ‘Hooligans’ abroad? Inter-group dynamics, social indentify and participation in collective ‘disorder’ at the 1998 World Cup Finals, British Journal of Social Psychology,  4, 359- 384.

Valentine, E., (1992), Conceptual issues in psychology (2nd ed.), London: Routledge.

Watson, J.B. (1913), Psychology as the Behaviourist Views it, Psychological Review, 20. 158- 177.

Webel, C. & Stigliano, T., (2004),  Are we ‘Beyond Good and Evil’: Radical psychological materialism and the ‘cure’ for evil, Theory & Psychology, 14, 81- 103.