WJEC A2 Psychology PY3 - Disadvantages of the Scientific Method

Notes for the Disadvantages of the Use of the Scientific Method essay in Section C of the PY3 exam


Scientific Method Disadvantage - Reductionist

1. REDUCTIONIST = disadvantage of the scientific method as it breaks human behaviour into its most simplistic components; scientific method uses expts where 'real life' is reduced down to the effect of one single variable on another single variable

(-) it is a disadvantage because

  • oversimplifies human nature and it fails to consider other factors which may interact to create a behaviour
  • the more we reduce a behaviour down to its constituent components, some would argue we have less understanding of the wider meaning/social context of that behaviour esp b/c human behaviour holds such complexity


  • Christiansen (1977) conducted some genetic research into crime; crime is likely to be caused by many different factors that all interact - genetic theories oversimplify the reasons for committing a crime b/c although crime is a social construct that changes over time in different places, genes remain the same, ignoring the environmental factors that may influence criminal behaviour eg child abuse
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Scientific Method Disadvantage - External Validity

2. LACK OF EXTERNAL VALIDITY =  scientific method often uses high controlled conditions = there is low ecological validity as they don't reflect a real life setting

(-) it is a disadvantage because:

  • findings from highly controlled scientific research are not always replicated in less scientific/controlled real world settings, so it is hard to generalise some studies beyond the research setting = if a study is conducted in an artificial environment, it is difficult to generalise any results to a real life setting


  • Loftus and Palmer's (1976) study on leading questions influencing memory was conducted in an artificial environment (car accidents on a video) and highly controlled conditions; not supported by Yuille and Cutshall's (1986) study of the effect of leading questions on real life witnesses of a violent crime. Demonstrates the difficulty of generalising findings in an artificial environment to the real world as the results can be very different
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Scientific Method Disadvantage - Nomothetic

3. NOMOTHETIC = by doing research studies that look for general laws of behaviour, generalising findings to everyone, it simplifies the complexities of human behaviour

(-) it is a disadvantage because: oversimplifies and often underestimates individual differences between people which means results cannot always be generalised as well as expected. Also, scientific controlled studies, that have led to theories, tend to use American, white, male Psychology students as pps - normally because American Psych students have to participate in so many psych studies to receive their degrees. Sample is therefore not necessarily representative (lacks pop validity) of the whole pop and so not generalisable, often findings don't apply to everyone


  • Buss (1989) often criticised for overemphasising similarities of male and female mate preferences between different cultures - actually several differences between mate pref for both genders that he didn't publish, also assumed everyone was heterosexualOften, if not always, findings cannot be generalised to everyone  due to complexity of human behaviour and differences between cultures = therefore no approach should be nomothetic?
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Scientific Method Disadvantage - Ethical Issues/Co

4. ETHICAL ISSUES/COSTS = often scientific investigations conflict with human rights and morals of pps

(-) it is a disadvantage because: pursuit of scientific knowledge might involve some sort of physical/psychological harm and one has to question whether the cost to the pps is justified by the benefits to society. Also, ethical issues are a disadvantage to the scientific method because some studies, that could potentially be very beneficial to society, haven't been carried out for fear of causing an ethical issue


  • Milgram's (1963) study involved some psych/phy harm to the pps. Whether the study is justified however is debatable - although 84% of pps were g or v glad to have taken part, 2% were unhappy or v unhappy to have participated. Arguable that all of the pps should have been happy to have taken part to make the study and its benefits more worthwhile
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Scientific Method Disadvantage - Publication Bias

5. PUBLICATION BIAS = disadvantage of the scientific method as it is the idea that some research is not published if findings are not expected or supportive of an intended hypothesis

(-) it is a disadvantage because: distort the apparent acquired knowledge within a given area, misleads readers of the published literature to draw conclusions not reflective of actual research conducted but not published; also underestimates or exaggerates the effects of variables


  • Lexchin et al (2003) suggests drug company sponsored research will more likely result in significant findings favouring the success of their drugs than not; distorts the view of public and specialised people within drug research that the drug is more effective than it actually is and not a true reflection of the drug's performance. This, in general, weakens the reliability of Psychology and scientific studies as they can appear less trustworthy for purposely not revealing all results
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Disadvantage - Internal Validity

6. LACK OF INTERNAL VALIDITY = very often, demand characteristics + experimenter bias occur in scientific research, which makes the results less valid

(-) it is a disadvantage because: demand c = pps may decide to change their behaviour based on what they think the study aim is or the 'Help You/Screw You' effect = where a ps changes behaviour consciously or unconsciously to help researcher or go against instructions based on own beliefs = results less valid as cannot be sure they reflect true pps behaviour; Heisenberg's Uncertainty Principle (1927) suggests no experiment is truly unbiased as confounding variables always have an effect, researchers will interpret findings subjectively and the effect of measuring a DV will always alter what is being measured = results less valid, findings based solely on bias?


  • Milgram's (1963) study lacks internal validity = obedience controlled observation could be a reflection of 'how helpful pps are in expts' rather than a study of obedience to authority - did pps change behaviour to be helpful or be obedient? were some pps more obedient due to confounding variables such as their own confidence or assertiveness? these doubts weaken the internal validity
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