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 effects of birth order on an individual's level of simulation has been found by studying eighteen rhesus monkeys and how they react in stimulating situations. A hormone called cortisol is produced during such instances. This study has been co-related with the humans but there are certain things which should be considered before the author makes such a comparison.

The study shows that when the firstborn infant monkeys face stimulating situations such as an encounter with an unfamiliar monkey, they produce up to twice as much of the hormone cortisol as compared to their younger sibling. This hormone is responsible for increasing the activity levels in the body. What about other stimulating scenarios such as encountering a wild animal or if it faces danger in some other form? Did the hormone production of the firstborn double even in such situations compared to the younger siblings? Information related to these have not been mentioned. The study must include all possible scenarios and the results should be recorded. If the firstborn monkey's hormone level increases even in other stimulating situations compared to that of the younger siblings, then it is true that the firstborns produce more cortisol hormones.

Next, the result of this study has been compared with that of human firstborns with a theory that even the firstborn humans produce higher level of cortisol in simulating situations. But there is no enough evidence or information to support this. What held good for the monkeys need not necessarily hold good for the humans even though we are from the same ancestors. If the results should hold good, then even the firstborn humans along with their siblings should be subjected to many stimulating situations and their hormone productions should be recorded and compared. If the results match with that of the monkeys then we can say that the clues from the study are true.

The author also mentioned that first-time mother monkeys had higher level of cortisol compared to those who had one or more babies earlier. This can be true since it is the first pregnancy for the mother monkey and hormonal imbalance can be very high compared to other mother monkeys who have already had one or more babies.

Thus, all the above arguments should be considered and analyzed properly by the author before he makes a conclusion on the study.