<p>General comment on the manuscript</p>
<p>The review is on an interesting topic relevant to psychology. It summarizes and explains the research on the social buffer effect, where cortisol or corticosterone stress response is lowered by the presence of another individual during the stress. The social buffer effect has been studied in humans and mainly in animal models. The reduction of stress response is dependent on the age of the subject, the relation to the buffer individual and the stress levels of the buffer individual. Mothers are good buffers to infants and the young, while stressed individual are worse buffers than non-stressed individuals. The research presented supports the conclusions.</p>
<p>The review is relevant on a frame of stress research and its detrimental effects on health. It primarily contains basic, quantitative and experimental research. A main strength of the manuscript is its clean and concise writing style. Themes are logically grouped together and detailed. The information presented is useful for practice and applications, since social buffering is presented as a direct solution to stress health problems, although is not a focus of the review. A main weakness of the manuscript is the method of article selection.</p>
<p>Major Observations</p>
<p>A review questions is not apparent, the affirmation on the third paragraph of the introduction suggests that the objective is to analyze the effectiveness of the social buffer effect.&nbsp; From my point of view, such a question requires a quantitative approach, in the form of a meta-analysis. A reframing of the review objectives would better describe the work that the authors are presenting. The information presented better answers an exploration of different aspects of social buffering that may be of interest.</p>
<p>A method or standardization section is required. The lack of a clear method of article selection feeds into the problem of the lack of a clear objective. This manuscript needs a section where the method is detailed. What was searched and where? Internet databases or other types of bibliography etc. A narrative-type review like this one might be relevant, but it still needs some type of systematic article selection. For example, in the second paragraph of “The social buffering effect” section, it says that the most representative research is reviewed, but what is the criteria for selecting the most relevant? This can be explained in its own section.</p>
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<p>Minor Observations</p>
<p>There are a lot of missing spaces (it reads “onthe effect” instead of “on the effect”, for example). Maybe is a problem with the document delivery system but see if they are missing in the original manuscript.</p>
<p>Some of the citations in the introduction could contain more recent articles. There is more recent literature on partial reinforcement effect, for example, Bouton, Woods and Todd, 2014 (https://doi.org/10.1016/j.beproc.2013.08.006). The citations in the first page regarding stress and its importance to health are mostly pre-2000.</p>
<p>The second paragraph on page 14 has different margins.</p>