There are a number of advantages to using scientific methods in psychology. Firstly an important aspect of imperial data is that it is objective, i.e. not affected by expectations of the research. So, without objectivity we have no way of being certain that data collected is valid. An example of this is seen with Gardner & Gardner. When they observed Washoe they might have judged that Washoe was using real words because they wanted her to succeed, for that reason the Gardners developed a strict set of criteria to make judgements. This shows that through objectivity it allows for there to be no bias evident.
Another advantage is that the scientific method allows for control. Laboratory experiment enables researchers to demonstrate causal relationships. The experimental method is the only way to do this – where we vary one factor (IV) and observe its effects of the DV. It order for this to be a fair test, all over conditions must be controlled and the best place for this is a laboratory. This is an advantage because if we can’t demonstrate causal relationships then we can’t be sure that, for an example, a person anxiety was reduced by the drug used.
Also the scientific method permits replication. If scientists record their methods and standardise them carefully so the same procedures can be followed in the future, i.e. replicated. This is an advantage because by repeating a study is the most important way to demonstrate the validity of any observation or experiment. If the outcome is the same this affirms the truth of the original results. An example where this can be seen is with Milgram and his research not having ecological validity. But the fact it has be replicated suggests that the study does have ecological validity. Throughout the history of psychology they have moved from Psychodynamic to behaviourism to humanistic and finally to cognitive. This is known as the Fundamental Shifts