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

A study that tried to establish a relationship between hormonal levels of first new born monkeys and human babies show that there is an increased level of the hormone Cortisol when these subjects faced unfamiliar or stimulating situations. This arguments is based on some vague facts, lacks proper quantification and presents an ambiguous causality for the conclusions drawn.

First, the study of Eighteen Rhesus monkeys does not necessarily prove that all the rhesus monkeys will exhibit the same characteristics. There is no quantitative information provided as to whether these monkeys were all infant monkeys, male or female adult monkeys. Without knowing the detailed parameters of the study all further arguments can be questioned for their validity.

On the other hand, while studying the human infants, relatively higher levels of cortisol have been observed by the researchers. But the term “relatively” does not convey the information properly. Does this mean that the higher levels of cortisol found in human babies were relatively higher than that of the monkeys’ or the human counterparts only. The argument does not indicate the number of human babies studied to come to a conclusion and the ratio of the firstborn humans to that of the remaining order. More clearly stated facts are required to strengthen the findings in the humans.

The fact that humans and monkeys can be compared and a conclusion can be drawn is appropriate only to a certain extent until and unless more stern evidence is provided. As far as the monkeys are concerned, only eighteen have been studied and are being compared to human infants, about whose size of population, we are unaware of.

Apart from children, the argument also predicates that first time mother monkeys also had a higher level of the hormone cortisol during their gestation period. However, any affirmative conclusions cannot be derived from the given fact. Did all the mother monkeys have a higher level of cortisol? What is the case about the human mothers during their pregnancy? There needs to be established a relationship which can aptly justify the argument.

As far as the argument goes, it can be concluded that this argument puts forth some facts which are possibly true but does not completely justify them. Moreover not every aspect of the order of the infants have been studied and complete quantified data evidence unavailable to support the argument.