Guten morgen PSYB4ers! For the benefit of my caffeine-fuelled, sleep-deprived self, I’ve composed a very brief set of notes for psychology as a science in fervent panic for today’s exam. If any of you unfortunate beings are in the same situation, then good luck to ya.

Discuss the limitations of the scientific approach in psychology. In other words, should psychology be a science?

Any question regarding the limitations of the scientific approach lends to this view.

So, outline the limitations, i.e.:

  • Reductionist
  • Deterministic
  • Ecological validity

Elaborate on them and flip them on their head. Reductionism may be negative in that we ignore other contributing factors, but by isolating variables, we can develop practical applications to treat disorders. Determinism may lend to a fatalistic outlook and see us as impossible of change due to the notion that we are controlled by extraneous forces outside of our control, but also allows us to predict negative behaviours, in order to prevent or control them etc. Use topic links too – these matters are easily discussed in the context of schizophrenia, mood disorders, offending behaviour etc.

Can psychology be a science?

Any question regarding the applications of the approach asks this question.

  • Unlike sciences of physics or chemistry that are more objective forms of science, psychology investigates humans. Thus, interaction between the experimenter and the subject raises various issues.
  • Experimenter bias – beliefs/wishes/attitudes/presence of psychologist affect the outcome of the study. Controlled to an extent by the double blind method, but even then, the general attitude of the psychology may still influence performance.
  • Demand characteristics – participant tries to guess the aim of the study, respond in ways they think the experimenter wants them to
  • Ethical implications – restriction and guidelines regarding what we’re allowed to do

Is psychology a science?

  • Outline criteria for science – paradigms, theory constructions, empirical methods and general laws
  • How closely does psychology adhere to the criteria?
  • Include topic links to demonstrate points – ie. biological approach/behaviourist utilises empirical methods, humanist/freud does not. General laws are established by Freud, the behaviourists etc.

Discuss reasons why psychology should adopt a scientific approach

  • Strengths of the approach, ie. practical applications, objective, high in internal validity, reliable etc.
  • Use topic links again, i.e. SSRIs for depression etc.
  • Offer counter argument – high in internal validity, but low ecological validity etc.


Hi all , I hope all of your exams and revision are going to plan. I thought I’d share some notes I’d made for approaches essays for the upcoming PSYB4 exam. I’ve included as many synoptic links as possible. Enjoy (or don’t)! 

Biological (came up in the June 2014 paper, so unlikely to come up for June 2014)

AO1 – Key assumptions underlying the theory

  • Darwinian theory – the evolutionary basis of behaviour (eg. fight and flight) and the notion that animals are inherently similar to humans, and that we can thus generalise findings from animal research to humans.
  • Determinism – human behaviour is determined by a combination of genes and genetic inheritance (Eg OCD/Schizophrenia). Animal behaviour is almost totally determined by genes.
  • CNS/Brain – both play an essential role in thought and behaviour. It is thus necessary to understand the workings/structure of the brain and NS more generally to understand behaviour. (eg. amygdala – responsible for emotions)
  • Chemical processes in the brain – responsible for different aspects of psychological functioning. Imbalance = abnormal behaviour/thought. (eg. OCD and serotonin/ Schizophrenia and excessive dopaminergic activity)

AO2 – Strength and weaknesses

  • S – Highly scientific methods of research 
  • eg. MRIs to give detailed pictures of brain structure/function. Controlled lab experiments for sleep patterns or to test drugs on animals.
  • High in internal validity
  • Developed new methods of investigation
  • Great advances in understanding the biological basis of behaviour
  • Replicability
  • BUT – scientific methods my not provide the same level of detail.
  • HOWEVER – biological app. does sometimes use case studies of brain damaged patients.
  • S – Useful theoretical applications
  • Explained OCD and schizophrenia, supported by empirical evidence
  • Offered explanations for criminality (extra Y chromosome theory)
  • Has furthered our understanding of certain behaviours/disorders
  • We can treat/prevent occurence
  • BUT – theoretical apps may be limited in their use – deterministic/reductionist
  • This raises various issues regarding free will – the ignorance of sociocultural/environmental influence on our behaviour is a negative outlook that raises serious implications for the judicial system – if criminals cannot help their actions, should they then be punished?
  • S – Useful practical applications
  • Led to the development of drug treatments – SSRIs for OCD, antipsychotics for Schizophrenia
  • Research within the approach has been put to good use
  • Relieved individuals of their suffering
  • BUT – biological treatments often have negative side effects
  • Only lead to partial improvement in symptoms
  • Other factors must be involved
  • W – Deterministic
  • Biological determinism – genes/neurotransmitters responsible for our behaviour eg. OCD caused by low levels of serotonin
  • Ignores role of free will
  • Resulting implications for society
  • People may adopt a fatalistic attitude – is there any point in trying to change if your situation is totally out of your control Ie. Criminality
  • BUT – also a strength – cause & effect – has allowed the development of effective drugs treatments such as SSRIs and the like – relieved many of the debilitating effects of their disorder
  • W – Reductionist
  • Psychological characteristics reduced to biological/physical processes
  • eg. neurotransmitter activity – serotonin/OCD – sociocultural factors ignored
  • Underestimates the role of other important factors on behaviour
  • May be better to explain behaviour from a sociocultural perspective/take a holistic view
  • BUT – adheres to scientific investigation – we can identify cause and effect to develop treatments by isolating single variables
  • W – More in favour of nature than nurture
  • Human behaviour explained in terms of heritability and biological processes
  • Overemphasis on the importance of these at the expense of environmental influence?
  • BUT – untrue to say the approach completely ignores this – phenotype influenced by genotype and environment


AO1 – Key assumptions underlying the theory

  • Thought processes influence behaviour – 
  • Conscious thought mediates behaviour by planning/controlling how to behave and monitoring that behaviour is appropriate for a given social situation.
  • Cog. factors that mediate our behaviour include perceptions, thoughts and feelings.
  • Unconscious processes, Ie. attention and memory also influence behaviour. Studies of subliminal perception suggest that we can be influenced by stimuli we can’t see or hear consciously.
  • Computer analogy – 
  • Mind processes information like a computer – drawing this comparison helps us to understand how humans process info.
  • Info is coded, processed, stored, retrieved from memory and a response is produced.
  • Information processing
  • Mental processes = information processing
  • Involves transforming, storing and retrieving info from memory
  • The use of models provides a mechanistic view of the human mind, which is useful in helping us to understand how we process info
  • Scientific methods of investigation
  • Believes that cognitive processes should be studied scientifically (ie. using lab experiments)
  • Brain affects our cognitive processes, so therefore, studying people with brain damage can be useful

AO2 – Strengths and weaknesses

  • S – Scientific methods of research
  • Highly controlled lab experiments collecting objective quantitative data
  • Eg. Sternberg’s experiment to investigate how we retrieve info from the STM
  • Findings are high in internal validity – extraneous variables are controlled (eg. environmental variables in Sternberg’s study)
  • Scientific research can general universal laws of behaviour, due to replicability (Ie. 7+-2 items principle)
  • BUT – uses some case studies of brain damaged patients – may or may not be generalisable due to unusual cases with limited samples
  • Some cognitivists rely on introspective reports, which are regarded as unscientific
  • S – Useful theoretical applications
  • Explains atypical behaviours such as schizophrenia/OCD/depression
  • Eg. people with OCD have an attentional bias and make catastrophic misinterpretations, leading to their compulsive behaviours
  • This is a strength as it has been useful and helped to develop effective treatments
  • BUT – with cognitive explanations it is difficult to establish cause and effect – does faulty thinking cause the disorder, or does the disorder cause the faulty thinking?
  • S – Useful practical applications
  • Eg. CBT aims to identify and challenge a patient’s negative thoughts – changing maladaptive thinking patterns into more adaptive ones
  • CBT has been effective (supported by Hollon et al) – who found that CBT was as effective as drug treatment
  • BUT – the biological approach would claim that OCD is a result of a lack of serotonin on the brain – this would lead to a completely different mode of treatment
  • If the underlying cause is not cognitive, then are individuals not receiving proper drug treatment?
  • W – Too mechanistic in its approach to explaining behaviour
  • Computer analogy depicts humans as little more than machines
  • Human attributes such as consciousness and self-awareness remain a mystery to cognitivists
  • The idea of a ‘man as a machine’ is seen as too simplistic and ignoring emotional and social facts in human behaviour
  • Eg. cognitive explanation for depression largely ignores the impact of emotions
  • Dehumanising
  • BUT – less reductionist that biological or behaviourist – explanations lie firmly at a psychology level
  • W -Uses lab experiments which often lack in ecological validity
  • Experiments into memory often involve the use of artificial stimuli and highly controlled conditions
  • Memorising trigrams is not exactly reflective of how we use memory in real life!
  • BUT – case studies of brain damaged patients are also used to investigate mental processes, which although less scientific, are more realistic
  • W – The approach is more interested in mental processes than actual behaviour
  • Research has focused on how we solve problems, how visual perception works etc.
  • Gives a limited view of the person as it doesn’t take into account their actual behaviour, just the info they output
  • BUT – this criticism is ironically the opposite of that made of the behaviourst
  • Perhaps the two approaches should be used in combination (eclecticism) eg. have combined for CBT – effective!


AO1 – Key assumptions

  • Determinism – extreme perspective – radical behaviourism. All behaviour is determined by past events. Knowledge of a stimulus allows prediction of a response/behaviour. Conversely, given a response, a stimulus can be specified. Behaviour, whether human or animal is controlled by external environmental factors.
  • Reductionism – complex human behaviour is said to be reducible to simple components (S-R bonds). Eg. behaving in a friendly way (complex behaviour) is involves a cluster of behaviours such as smiling, laughing and saying nice things. Each of these behaviours would be learned from the reinforcement of S-R bonds to form complex behaviour.
  • Environmentalism – Extreme view that all learning comes from experience and that heredity has no role to play
  • Biology/genetics play a minimal role
  • Behaviourist perspective falls firmly on the side of nurture
  • Empiricism – only that which can be observed, measured and recorded should be scientific psychology
  • Thoughts and feelings cannot be observed, therefore they are not within the scope of behaviourism
  • ‘Psychology as the behaviourist views it is a purely objective, experimental branch of natural science which needs introspection as little as do sciences of chemistry and physics. It is granted that the behaviour of animals can be investigated without appeal to consciousness’

AO2 – Strengths and weaknesses

  • S – Use of scientific methods 
  • High standards of observation, measurement and replication
  • By concentrating on observable behaviour & using the experimental method, they were able to produce verifiable theories about behaviour
  • Allows extraneous variables to be controlled/high internal validity
  • Conclusions about cause and effect can be drawn = enhanced understanding of behaviour
  • Driving force in development as psych as a science
  • BUT – use of animals in research means that findings may not always be generalisable to humans
  • S – Useful theoretical applications
  • Offered explanations for acquisition of phobias and criminal behaviour through classical conditioning
  • Parsimonious theory (unlike psychodynamic) – doesn’t go beyond empirical evidence  and explains facts in the most economical way
  • BUT – ignores the role of biological processes in human behaviour – research evidence suggests that criminality may well be genetic
  • S – Useful practical applications
  • Treatments for phobias – systematic de-sensitaisation
  • Offending behaviour – token economy
  • Practical apps. in education and the training of guide dogs too
  • Has made important contributions which are useful and beneficial to society
  • BUT – whilst using behaviourist principles to treat phobias/offending behaviour in  controlled way seems to be effective, effects don’t always generalise to every day life
  • W – Deterministic
  • eg. explains all behaviour as resulting from environment/past experience (environmental determinism)
  • Denies existence of free will – are individuals not responsible for their own behaviour?
  • If criminality is a result of past experience, then should criminals still be held responsible for their actions?
  • Similar to bio approach/contrasts humanistic
  • BUT – more positive/less fatalistic than the biological approach – if offending behaviour is LEARNED, then it can also be UNLEARNED
  • W – Reductionist
  • Reduces complex behaviour to S-R bonds
  • Such as offending – conditioning
  • Mechanistic/overly simplistic
  • Ignores the role of genes and cognitive processes
  • ‘Degrading and scientifically inaccurate’
  • IN CONTRAST – SLT takes into account the role of these mediating cognitive factors in learning
  • W – Nurture, rather than nature – 
  • All human behaviour = environmental through conditioning
  • Ignores the nature side of the argument – perhaps taking an interactionist approach is the best way to understand human behaviour
  • IN CONTRAST – Biological approach comes down on the nature side, providing evidence of the role of genes and neurotransmitters in our behaviour


AO1 – Key assumptions

  • Social context – learning takes place in a social context – SLT needs to take account of other people in learning process as a result. eg. child may learn gender role by observing adult models in a social context
  • Observational learning – we learn through observing how others behave in social situations, observing rewards/punishments received for behaving in certain ways also (vicarious reinforcement).
  • The people we observe are models, and the characteristics of said model influences whether or not the observer imitates
  • Social conditions – Learning through observation doesn’t always result in performance. Social conditions have to be correct.
  • eg. We may observe models on TV that it is necessary to curtesy when meeting the queen
  • Said behaviour only will be imitated if we actually meet the queen.
  • Language – Language and other forms of symbolism allow us to turn experience into conscious though to reflect and plan future behaviours
  • These are mental processes and NOT passive responses
  • (Could link to Vygotsky – child cog. development)

AO2 – Strengths and weaknesses

  • S – Adopts scientific methods
  • eg. Bandura conducted controlled lab experiment in which children were exposed to either an aggressive, or non-aggressive role model. Children who observed an aggressive adult model displayed aggressive acts onto a bobo doll.
  • Experiments such as this = high internal validity/high control over EVs = useful in establishing cause and effect
  • Furthers our understanding of human behaviour
  • BUT – studies such as bobo doll study criticised on the grounds of ecological validity
  • Children may also respond to demand characteristics = lowers validity of study
  • S – Adopts a compromise position in the free will/determinism debate
  • Soft determinism – Bandura proposed the idea of reciprocal determinism – interaction between our environment and our cognitive processes = both influence each other = behaviour
  • We have a ‘degree of free will’/personal agency
  • Less fatalistic – we are not passive. More pos. than determinism
  • IN CONTRAST – behaviourism sees free will as an ‘illusion’- all behaviour shaped by past events
  • S – Useful theoretical applications 
  • Applied to explain offending behaviour; a child may observe a role model receiving a reward (ie. popularity) for stealing sweets
  • Child learns through vicarious reinforcement and may imitate behaviour later on.
  • Also, the concept of self-efficacy as defined by Bandura as ‘as one’s belief in one’s ability to succeed in specific situations’ has been adopted by health and sport psychology
  • Pos. impact on society
  • BUT – applications are limited in their use – does SLT ignore biological factors?
  • W – Ignores the role of heredity/biology
  • Biological approach states that aggression is due to hormones/brain abnormality/genetics
  • Is SLT reductionist in that it explains behaviour at an environmental level, ignoring biological factors
  • BUT – acknowledges internal mental processes, so, less reductionist than biological in a way
  • W – Criticisms of Bandura’s experiments
  • Presence of demand characteristics due to nature of observational experimentation
  • Artificial environment
  • Little external validity – very rarely will an adult demonstrate aggression on a bobo doll and allow a child to imitate
  • Research on which the theory is based = weak, theory is weakened as a result
  • W – Not very good at explaining the learning of abstract ideas/concepts
  • Such as justice or fairness, through observation.
  • How can we learn a complex concept simply through observing role models?
  • Approach is limited and only explains some types of learning
  • BUT – the approach has been influential, acting as a bridge between behaviourism and cognitivism

Freudian/post-Freudian theories (came up in the June 2014 paper, so unlikely to come up for June 2014)

AO1 – Key assumptions

  • Unconscious processes – mental processes can occur at conscious, pre-conscious and unconscious levels. Human behaviour largely determined by unconscious motives and conflict. Unconscious stems from the three elements/tripartite structure of the personality – id, superego and ego, which are all in constant conflict.
  • Defence mechanisms – Our understanding of ourselves is distorted by defence mechanisms. Our little insight into our conscious mind does not provide an accurate picture of who we are.
  • Through these mechanisms (eg. repression, displacement) we distort reality to avoid the damaging psychological consequences/pain of the truth.
  • This is how we protect the conscious mind from anything painful or disturbing in nature
  • Childhood experiences – Early childhood experience have significant influence on adult personality/behaviour
  • How the child copes with conflict and unpleasant experiences in childhood will be repeated later on
  • Ie. Bowlby suggested that an infant who does not secure attachment with the mother in the first year of life will, without fail, have problems later in life (ie. inability to form close relationships)
  • Case studies – The best way to study humans is through the case study method. This allows the individual to be studied in detail – what is said and done can be interpreted by the analyst for unconscious/underlying motives.

AO2 – Strengths and weaknesses

  • S – Highlights the importance of childhood experiences
  • eg. John Bowlby – no secure attachment with mother = issues in later life forming close relationships
  • Important basis for psychological functioning
  • This is now accepted in psychology and professional areas such as social work and psychiatry
  • BUT – perhaps the importance on close early relationships is overemphasised – many children who have been deprived of an attachment with their mother in the first year of life go on to live perfectly normal lives
  • This shows that the theory is limited in its explanation of psychological development
  • S – Useful theoretical applications
  • S – Some useful practical applications
  • Ie. free association/dream analysis etc. – implemented to treat phobias – uncover the underlying unconscious thoughts that cause them
  • Freudian case studies = effective
  • BUT – Freud recorded his case studies unreliably – not objective, open to researcher bias
  • Many patients he treated were NOT fully recovered
  • W – Deterministic and pessimistic 
  • Humans are inherently bad
  • Perspectives on childhood experience/psychosexual development = troubling = ie. oedipus etc.
  • Inappropriate and overstated?
  • Also, many children that have negative experiences/phases in childhood go on to have perfectly normal adult lives
  • W – Relies on the case study method
  • eg. Little Hans
  • Cannot generalise from one case study, or even a few, to ALL children
  • Accuracy questionable – not objective, open to researcher bias
  • Unscientific
  • BUT – attempts to establish GENERAL laws of behaviour, which is what scientific psychology strives to achieve
  • W – Unscientific and untestable
  • Unfalsifiable hypotheses
  • Abstract concepts
  • Immeasurable
  • BUT – again, attempts to establish general laws of behaviour and views id, superego, ego as innate – scientific to some extent


AO1 – Key assumptions

  • Free Will – each human being is an active agent, able to choose, control and change their own behaviour
  • We control how we think and feel
  • Holism – the best way to explain, study and treat behaviour is by looking at the person as a whole rather than reducing them to component parts – ‘the whole is more than the sum of its parts’
  • Conscious thought – each person is a rational and conscious being and is no dominated by conscious, primitive instincts. It is best to study human behaviour by asking people about their conscious thoughts eg. via. interview .
  • Each person is unique – therefore, it is important to focus on the private,subjective experiences of each individual, rather than taking an objective approach. Humanism rejects the scientific approach.

AO2 – Strengths and weaknesses

  • S – Acknowledges the role of free will 
  • Humans are active agents, we have the power to choose and decide on our own behaviour. Person centred therapy encourages clients to develop their own solutions – optimistic
  • Places responsibility on the individual and sees them as capable of change
  • BUT – concept of free will not consistent with assumptions of science – humanism lacks empirical evidence
  • S – Takes a holistic view – 
  • Acknowledges the complexity of human thought and behaviour by considering them as a ‘whole’
  • BUT – holism, unlike reductionism, doesn’t lend itself to scientific psychology – lacks empirical evidence to support its claims
  • S – Some useful theoretical/practical applications – 
  • Maslow’s hierarchy of needs useful in business and education
  • Client-centred therapy for stress/anxiety/divorce/bereavement – a more ‘person-centred’ alternative to Freudian psychoanalysis
  • Approach has benefitted society – useful for mild depression/anxiety
  • BUT – limited in use – does not successfully treat more serious disorders, such as schizophrenia, wherein people often lack insight into their conscious thoughts and are unable to discuss them rationally
  • This raises further issues into the key assumptions underpinning the theory
  • W – Unscientific
  • Lacks empirical evidence to back up claims that other approaches DO have. Eg. The biological approach has a wealth of supporting evidence and is largely a more accepted psychological approach
  • Complete rejection of the scientific approach into studying human behaviour because emphasis is placed on the private subjective experience of the individual
  • No support for theory – is it completely unfounded?
  • W – Relies on unstructured interviews
  • Cannot be replicated
  • Hard to analyse – involve collecting qualitative data regarding a person’s thoughts and feelings (private subjective experience)
  • Interviewer might stray from focus
  • Relies on participants having a good insight into their own thoughts/feelings and reporting them accurately (memory is an issue here)
  • BUT – qualitative methods are useful, providing more rich, detailed info about experience of humans than experimental methods can provide
  • They can help us understand WHY people think or behave in a certain way
  • W – Problems with the concepts of free will and self-actualisation
  • Some needs are missed from self-actualisation and it is perhaps too simplistic a view of human thought and behaviour
  • Abstract concepts which are not directly observable, objectively measurable, or even definable
  • Unfalsifiable – unscientific

Eclectic approach

Click Here to see my notes on the eclectic approach, complete with an essay plan 🙂

AQA PSYB4 PPQ – Discuss how the biological approach helps psychologists to understand human behaviour. In your answer, refer to two topics you have studied in psychology.

Just thought I’d post my most recent psychology essay! I’ve only just started learning the PSYB4 module, so I’ll have some better essays on this soon, as well as some PSYB3 essays.

The biological approach believes humans have evolved through Darwinian evolution and therefore, certain behaviours have evolutionary explanations. For example, we have evolved to have a ‘fight or flight’ response to threatening situations. Our sympathetic nervous system prepares the body for action by releasing adrenaline and increasing heart rate, and this is said to have an evolutionary basis as it aids survival. However, the biological approach s criticised for focusing too much on the nature side of the debate. This is a weakness as it may be an overemphasis on the importance of evolutionary factors and biological processes at the expense of psychological and environmental factors. Yet, it is untrue to say the biological approach ignores environmental factors completely, as it is known that the phenotype is influenced by both genotype and the environment. For example, in a situation where identical twins, who share the same genotype, are separated at birth, can potentially have different phenotypes, which can reflect in both their personality and their physicality as they are treated differently by their parents. Therefore, this is a clear acknowledgement of environmental influence by the biological approach, as it recognises how those who are expected to exhibit the same behaviour as they share exactly the same genetic make up, can show different behavioural tendencies depending on how they’re brought up. Furthermore, the diathesis stress theory of schizophrenia acknowledges how an individual may be genetically predisposed to developing the disorder, but that it takes a stressful life event to trigger the disorder. This is a clear strength of the biological approach, as a knowledge of genetic predisposition can lead an individual to avoid the environmental stress factors that incite the disorder, and therefore, deter its onset altogether.

Another assumption of the biological approach is that human behaviour is strongly determined by our genes and genetic inheritance. For example, it is thought that disorders such as OCD and schizophrenia may be genetic, as evidence shows that they run in families. Evidence from this comes from Pauls et al, who found that those with a first degree relative with OCD are more likely to develop the disorder. Furthermore, Kendler found that those with a first degree relative with schizophrenia are 18 time more at risk of developing the disorder themselves. However, the biological explanations of OCD and schizophrenia are deterministic, claiming that the disorder is beyond the control of the individual. This is a weakness as it ignores the role of free will and sees us as powerless to change. This has implications for the criminal justice system, as it raises questions such as ‘are criminals responsible for their own behaviour?’ meaning that custodial sentencing may be an unwarranted and unethical punishment, as offenders are unable to stop themselves from committing offences. In addition, this deterministic view also has negative implications for society, those with OCD and schizophrenia may adopt a fatalistic attitude, assuming that they cannot change their behaviour because it already fixed in their genetic make up.

Furthermore, the approach is reductionist as it explains OCD and schizophrenia at the level of genetics, ignoring factors such as upbringing and socio-cultural factors, despite compelling evidence that schizophrenia may be a result of labelling. This is a weakness as it is dehumanising, presenting humans as biological machines, underestimating the role of other important factors on our behaviour. For example, it may be better to explain human behaviour from a social or cultural perspective, as sociocultural theories, such as labelling theory, have shown clearly the damaging effects of labelling an individual with medical terms such ‘schizophrenic’ or ‘mentally ill,’ as others may interpret normal behaviour as a symptom of their disorder, and they can become ostracised from society as a result. In spite of this, biological reductionism is also a strength, as by isolating just one factor, it allows researchers to investigate that factor scientifically in order to establish cause and effect relationships. For example, experimental research is useful, where an IV is manipulated and all other variables are controlled, as by determining causation, researchers may be able to find treatments to aid those with behaviours that lessen their quality of life.

The biological approach assumes that the central nervous system, especially the brain, plays an essential role in thought and behaviour. For example, the amygdala in the limbic system plays a role in emotions. Evidence from this comes from Morris et al, who found that the amygdala shows high levels of activity when a person is shown fearful faces, suggesting that this particular area of the brain plays a role in our ability to recognise fear, thus implying that our reactionary behaviour has a biological basis. This is a strength as it demonstrates how the biological approach has been useful in explaining how and why we are able to recognise fear in another person. This may serve the evolutionary function of keeping us safe as if we can recognise emotion in someone else we can avoid the dangerous situation ourselves. Furthermore, this research is highly scientific. Morris used PET scans which is a precise and objective method of investigation. This is a strength of the biological approach as the research is high in internal validity and can be replicated precisely. This scientific approach enables psychologists to develop universal laws of behaviour and make predictions about human behaviour.

The biological approach believes chemical processes in the brain are responsible for psychological functioning. For example, OCD is though to be caused by low levels of serotonin and schizophrenia is thought to be a result of excessive dopaminergic activity. This is supported by Seeman et al, who found six times the density of D4 receptors in the brains of people with schizophrenia, supporting the claim that the activity of the neurotransmitter dopamine may cause the symptoms of schizophrenia. This is a strength of the approach as there is a clear link between schizophrenia and an increase in dopamine receptors, inferring that chemical processes are indeed responsible for schizophrenic behaviours. Research such as this has developed in useful practical applications, such as the development of drug treatments. For example, SSRIs for OCD and antipsychotic drugs for schizophrenia. This is a strength as it shows the biological approach has been beneficial and has made important contributions to society, improving the quality of life  for sufferers by lessening the debilitating effects of their disorders. However, the neurochemical explanation of schizophrenia is limited as there is evidence to suggest that family dysfunction, such as high levels of expressed emotion can trigger the development of the disorder. This highlights the importance of considering both the influences of nature and nurture on our behaviour, as the treatments that have resulted from this theory, such as family therapy, have been effective, as Hogarty et al suggests that such therapy can significantly reduce relapse rates.