Science itself is only a science because it is has control, predictability, replicabilty (being able to replicate the experiment), objectivity, and be falsifiable (where a theory can be proved correct). It is also nomoethic, reductionist, deterministic and empirical (records information from direct observation). Psychology can be classed as a science because it contains the same characteristics.
An advantage of applying the scientific method to psychology is that researchers have increased control over the IV and can have standardized procedures, which increases the researches’ reliability and replicablility. For e.g. Loftus and Palmer showed the same participants the same clips of the same car crash and gave them the same questionnaires (apart from one differing leading question), and they were all tested in the same environment. This helped ensure the reliability of their eyewitness testimony. However, although lab experiments are highly scientific, case studies and natural experiments are not.
