The following appeared as part of a letter to the editor of a scientific journal."A recent study of eighteen rhesus monkeys provides clues as to the effects of birth order on an individual's levels of stimulation. The study showed that in stimulating situ

The Writer of the argument makes a strong conclusion about the positive effect of birth order on individual’s levels of stimulation based on a study of eighteen rhesus monkeys. However, the conclusion is based on a number of premises that can be accounted for in other ways as well.

First and fore most, the editorial’s author mentions a study on eighteen rhesus monkeys, yet fail to explain whether the sample studied is representative of the larger population or not. For that matter, the conclusion is not convincing in its current form. As you know, in research studies, the larger and more representative the sample of study, the more reliable and valid the findings are. Without solid explanations that the sample used in the argument was representative of the larger population, the findings of such a study is neither reliable nor valid.

Even assuming that the sample used in the study was representative, the conclusion is based on another crucial assumption that no other factors affecting the amounts of hormone, which are produced by the monkeys, are present. Absent any evidence that this is the case, I cannot accept the conclusion. The writer of the argument must supply concrete explanations regarding the fact that high levels of cortisol might have been caused by other factors that were not considered in the study. Perhaps, the firstborn monkeys produced more hormones due to sexual desires or some environmental factors at the time of birth regardless of the birth order. Or maybe the mother’s body caused the increase in the production of hormones, not the stimulation. In short, without ruling out these and other possible scenarios, the conclusion lack any merit whatsoever.

Finally, the argument relies on a false analogy between humans and monkeys that human also produce relatively high levels of cortisol in stimulating situations. In order for monkeys to act as a model or reference for humans to draw similar scientific conclusions, the writer of the argument must explain that all the factors involving the stimulation and production of hormones in humans and monkeys are otherwise essentially the same. However, the writer of the argument does not offer any evidence in support of the conclusion that humans response to stimulations in the similar way, yet alone to prove that birth order affect the individual’s levels of stimulation. If so, the author cannot defend the conclusion on the basis of what might be a false analogy between humans and monkeys.

In conclusion, the argument is logically flawed and therefore unpersuasive. To strengthen it, the editorial’s author must either explain that whether the sample used in this study were representative, or elaborate on the fact that humans and monkeys are similar in all respects. Finally, to better evaluate the author’s conclusion, I need to know that other factors, which might affect the results of the study, were not present during the experiment on the above-mentioned monkeys.