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 author of the letter to the editor of a scientific journal postulates that the levels of hormone cortisol produced by rhesus monkeys is correlated with their birth order. His conclusions are based on unsubstantiated assumptions. Without additional evidence, several other explanations can account for the incomplete information provided by the author.

First alternative explanation, that can could rival the proposed conclusion could be that inexperience and insecure primipara, having much higher levels of cortisol, can pass the ability to produce the hormone in excess to her firstborn baby. Mother of the second monkey, on the other hand, feeling much confident and being more predictable, would most probably experience much less stimulating, stressful situations. In the letter to the editor, the author mentions that it is the infant monkey who produce up to twice as much of this hormone. Provided that the production of cortisol attenuates with growth of the baby, explanation that it is the mother's stress that induces elevated levels of cortisol would be well justified.

Secondly, author implies that humans, similar to monkeys also produce relatively high levels of cortisol in stimulating situations. Wording of the sentence providing the evidence about humans is ambiguous and vague. Author states that humans also produce relatively high levels of cortisol, but potential reader doesn't now if the hormone level is relative to the levels of monkeys or relative to the levels of other humans.

Furthermore, the stimulating situation that caused higher levels of cortisol in humans is completely different from the situation that raised hormone level in monkeys. With monkeys, cortisol was released while encountering unpleasan event. In humans, however, it is the very happy situation that caused horom elevation. Thus, considering the evidence given, release of cortisol in humans and monkeys can be governed by completely different mechanisms and different stimulus.

To recapitulate, author's line of reasoning has several gaps that requires additional information for the argumentation to be sound. Author juxtaposes two different situations concerning two different species. Drawing conclusions from so distinct experiments is unreasonable and highly speculative.