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

A study was done on rhesus monkeys to provide the effects of birth order on levels of stimulation and it was proved that firstborn infant monkeys produce twice the amount of cortisol hormone. This was also proved in humans that, fist borns have high cortisol levels as compared to their siblings. The study also reveal that the first time monkey mothers had higher level of cortisol than the other monkies with several offsprings. However, a conclusion can not be drawn with only the started evidence by the author. More evidence is required to substatiate the claim.

Firstly, it is said that the study was done on eighteen rhesus monkeys. This could have been a sample size which is not a true representative of the population. So more information on the sample's representativeness is required for us to draw up a conclusion. As the argument is further analysed, we are not told anything of the environment of the monkeys. A lot of questions come can be paused regarding the environment because this might affect some hormone levels. The environment will determine the type of food these species are feeding on. More information on whether the eighteen were taken from the same environment or not will give us a profound view of the same specie leaving in different areas.

Secondly, nothing is stated on the ages of the monkeys that were selected. Levels of hormones can change with age and hence that information would help in making our argument strong. For example you can not compare oestrogen levels of a 21year old and that of a 40 year old. Information the cortisol levels of monkeys of different ages could have helped in making the argument credible.

Furthermore, the author gives us an example of a study conducted on humans that the hormone cortisol is also high in first borns. This does not make the argument plausible, its like comparing a donkey and a horse. Studies which could have strengthened the argument could be studies of different species of monkeys. This would have give a better comparison on how this hormone varies on the different monkey species.

The author concludes with a study which was conducted on monkey mothers. Which showed that first time mothers had high levels of cortisol when compare to those who had several off springs. From the evidence stated by the author a conclusion can not be drawn if more evidence is given to substantiate the argument. It could be other factors that are believed to affect hormonal levels like age, environment and the specie type are taken into consideration. Such information would help in making the argument plausible.

Above all, a conclusion can not be drawn from the evidence state by the author. More evidence is required for a credible conclusion to be drawn.