The basic study - Baker and Barenbaum (2007) 03

 The critical points were mainly three. One is that, those participating in the study were all American psychology students and this could mean that extending the findings to people who are at the outside; this quite limited group might be not valid.
 Next point is that, the assessment was in part of self-assessment and this might be that the participants’ answers were reflected by a social desirability.
 For example, the participants might felt as saying that they would deal with the stressful situation by ‘calmly taking five deep breaths, and taking it through with their friend’ was more acceptable instead of saying that they would ‘throw a rock through the nearest window’ to release the stress. The last point is that, at the beginning of this study that participants were all asked to identify a stressful situation and write about their feelings and properly, this might be regarded as unacceptable.
 The researchers were not to know of any stressful experience, these students might recently had that and making them as think about them and write down their feelings could have resulted in making the students feel a lot worse.