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 situations (such as an encounter with an unfamiliar monkey), firstborn infant monkeys produce up to twice as much of the hormone cortisol, which primes the body for increased activity levels, as do their younger siblings. Firstborn humans also produce relatively high levels of cortisol in stimulating situations (such as the return of a parent after an absence). The study also found that during pregnancy, first-time mother monkeys had higher levels of cortisol than did those who had had several offspring."

Write a response in which you discuss one or more alternative explanations that could rival the proposed explanation and explain how your explanation(s) can plausibly account for the facts presented in the argument.

According to the given argument, it is stated that the effects of birth order has an effect on the individual’s level of stimulation.To prove this the humans are compared to the rhesus monkeys who show similar level of hormonal changes in specific situations.There can be alternate explanations which could challenge the research as being inconclusive.

First of all we do not know how the test of the comparison of Rhesus monkeys to humans is a credible one.We could test the humans with another breed of monkeys or any other who might not show the same level of hormonal changes when put in the exact same situations in which the humans were tested. In a hypothetical situation, we could test the humans against a lion species and see that the hormonal changes in both of the species are same.So does it mean that Humans can be compared to lions and appropriate conclusions can be drawn from it? We need specific proof that rhesus monkeys are comparable to human beings.

The conditions on which the humans and the rhesus monkeys are also very different which does not give us any specific evidence about the hormonal changes in specific situation.It is said that the Cortisol levels in monkeys go us when they encounter an unfamiliar monkey.This Cortisol level goes up because the monkey senses danger.On the other hand the Cortisol levels in firstborn children go up when they see a familiar secure figure such as there parents.This is in complete contrast to situation where the Cortisol levels of the monkeys go up.We do not know how the firstborn human might react when faced with an intimidating situation such as encounter with and unfamiliar human being.This proves that the study needs more research in order to arrive at a definite conclusion.

The main goal is to find out the effect of birth order on an individual’s level of stimulation. The last sentence seems to present only the conclusion based on the tests on the Rhesus monkeys.There is no mention about how humans go through these hormonal changes in the exact same situations.Therefore we do not have any evidence to evaluate whether first time mothers have the same levels of cortisol as the monkeys have. Therefore argument ends in a very inconclusive manner.

Since the above argument does not provide us with a lot of concrete evidences supporting the claim of the author, there are many alternative explanations which can arise from it which can damage the conclusions derived by the scientists.