grade gre essays

[salonie dua]

"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."

 

The above argument concludes from a study of eighteen rhesus monkeys that firstborn infant monkeys produce up to twice as much cortisol as the younger siblings. The instances that form the underlying basis of the argument include a stimulating situation of encounter with unfamiliar monkey and a hypothesis that firstborn humans also produce relatively high levels of cortisol. However, this conclusion is rife with holes and assumptions.

Firstly, the fact that only 18 rhesus monkeys were picked for the study questions the extent of veracity of the same. The sample size is too small to be representative of a particular sect of species. It is highly likely that these 18 monkeys ended up showing similar results due to various reasons. They were probably chosen from the same area or same extended family and thus have similar physiological reactions. The method of this statistical analysis seems doubtful.

Also, an encounter with an unfamiliar monkey is too risky a situation for a newborn monkey and will necessarily result in an overly perturbed reaction. Even adults respond to such a situation with fear and caution. We are unaware of other simultaneous conditions prevalent along with the fact that the newborn was coming across a stranger monkey. There might have been other factors present that would have increased cortisol levels when studying the firstborns which could have been absent in case of the analysis of the rest of the siblings.

Another flaw I would like to point out is that I’m not sure how strong the link between the cortisol production of firstborn humans and firstborn monkeys is. While it is true humans are the evolved products of monkeys and therefore they share similarities, the author hasn’t established proof for this connection. Moreover, the stimulating situations considered in both is very different. While the one for monkeys tends to induce fear and discomfort, the return of a parent will most likely produce joy. The reasons for cortisol production is dissimilar and hence questionable.

In the last sentence, the author mentions that first time mothers have higher level of cortisol when compared to mothers who have had off-springs before. He uses this prove that firstborn monkeys thus have the higher cortisol levels. However, this argument is flawed. Mothers’ cortisol levels are related to their pregnancy and serve their biological processes as they need extra energy at a time when their body undergoes the distress of carrying another life for the first time. This is not a gene that is passed on to the first child. There is no such explanation offered by the author.

Thus, while the study tends to confirm that firstborn monkeys have higher cortisol levels, there are many questionable points which debunk the author’s theory.