Psychology and the Scientific Method

• The scientific mehtod refers to a body of techniques  for investigating, acquiring or developing knowledge.

• For a research method to be scientific it must be undertaken in a controlled enviroment, make objective measurements, allow the researcher to validate or falisfy a theory and be replicable.

• The four approaches of psychology are all different levels of psychology, the behavioural, cognitive and biological are seen as more scientific compared to the psychodynamic approach.
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CAN MAKE OBJECTIVE MEASUREMENTS

Objective measurements are seen as measurements that are not biased through demand characteristics or research bias.

In the biological investigation of Eden et al (1996) we can see that they were able to make objective measurements through the use of fMRI scans. By comparing the sequence of brain activation within dyslexic and non-dyslexic children when they were reading. Eden et al was able to show that dyslexia is associated with a lack of activity within the posterior visual cortex.



ALLOWS US TO DESCRIBE, PREDICT, UNDERSTAND AND CONTROL BEHAVIOUR.

Our ability to control behaviour is an advanatage as it means that psychologists can demonstrate ways in which we can enhance appropriate behaviour or stem inappropriate behaviour.

The lab experiment Bandura, Ross and Ross (1961) shows that psychologists can control aggressive behaviour by controlling the violent contents on TV that the children watch.

ALLOWS US TO VALIDATE OR FALSIFY A THEORY.

 Validation allows us to demonstrate that a theory is correct, whilst falsification allows us to prove that a theory is incorrect so the theory can be discounted or amended according to the new evidence.

This can be shown through the laboratory experiment by Levinger and Clark (1961) which investigated Freud's (1951) theory of repression. Freuds theory of repression is criticised due to his use of case studies and lack of scientific evidence. The theory of repression states that anxiety provoking memories may become locked away in the unconscious mind of an individual in order to protect that individual from further harm.

Levinger and Clark found that more emotionally neutral words could be recalled by participants than emotionally arousing words, the theory of represion was validated. Anxiety provoking information can be repressed.

ALLOWS US TO TEST FOR CASUALTY

This allows the researcher to be certain that the manipulation of the independant variable alone can cause change in the dependant variable.

In the Field experiment Brown and Kulik (1977) they were able to demostrate that the manipulation of the independent variable (the assassinations of famous Black-Americans and the assasination of famous White-Americans) cause the change in the dependant variable (the maount of information that the participants could correctly recall about each event).

In this study they could prove that the significance of the event to the person was the factor that led to enhanced recall.

COLLECTION OF OBJECTIVE MEASUREMENTS.

Whilst objective measurements allow us to identify patterns of behaviour they do not help us to understand why a particular behaviour occurs.

E.g. In the biological investigation of Eden et al (1996), the use of fMRI scans showed that dyslexia is associated with a lack of activity within the posterior visual cortex, but not why this inactivity occirs in someindividuals and not others. This objective measurements only allow us to quantify and not quantify human behaviour.

SUCH RESEARCH CAN LACK ECOLOGICAL VALIDITY.

This is a disadvantage because psychologists may not be bale to generalise the results about behaviour measured in artificial, controlled conditions to behaviour in the real-world.

Bundura, Ross and Ross (1961) concluded form their lab experiments that aggression is learnt via observation and imitation. Whilst Fanagan (2000) has shown that higher levels of aggression are associated with higher levels of the hormone testoterone.

Both of these studies us the scientific method, but they present contradictory information, with the former supporting the nurture side of the nature-nurture debate and the latter supporting the nature side of the nature-nurture debate.

WHILST TRYING TO DETERMINE WHETHER TO VERIFY OR FALISIFY WE CAN MAKE EITHER A TYPE I OR TYPE II ERROR.

A type I error occurs when we incorrectly reject a hypothesis that is in fact true whereas a type II error occurs when we fail to reject a hypothesis that is in fact false.

Evidence to support the complicated nature of Type I and Type II errors can be seen in Levinger and Clark (1961) and Bradley and Baddeley (1990). Levinger and Clark found that more emotionally neutral words could be recalled by participants that emotionally arousing words, Freuds theory of repression was validated.

However when Bradley and Baddeley extended Levinger and Clarks research by testing participants both immediately after the study and 28 days later found that the emotionally arousing words were significantly higher after 28 days. A finding that appears to contradict Freud's theory of repression and one that could lead us to either correctly or incorrectly falsify such a theory.

WHILST PSYCHOLOGISTS USING THIS METHOD BELIEVE CASUALTY CAN BE SHOWN, OTHER PSYCHOLOGIST BELIEVE IT IS WRONG TO TRY AND EXPLAIN HUMAN BEHAVIOUR IN TERMS OF CAUSE AND EFFECT.

Human behaviour is complex and people can act in highly unpredictable ways, it seems inappropriate to try to control them in such a way that only one variable will be impacting upon their thoughts and behaviour.

E.g. Brown and Kulik (1977) suggest that the manipulation of the independent variable alone caused the change in the dependant variable, but it could be argued that recall on the day of testing was also effected by the mood of the participants, their level of motivation and media reports they may have recently been exposed to.