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

Dependence of hierarchy in Rhesus monkeys, as the author remarks, is based on individual levels of stimulation, analogous to that found in humans. But his claim is based on certain assumptions and is rife with loopholes that argue otherwise.

The subjects, eighteen rhesus monkeys under test, might have been collected from the same geographic location, having similar climatic factors. Had one monkey been collected from each place that houses the rhesus species, all across the globe, the inferences could have been different. Moreover, a meager study of only eighteen monkeys might not produce substantial results about their general behavioral pattern and response to stimulating situations.

The author states that first born monkeys produce cortisol levels twice as high as its younger siblings. But there can be anomalies about this notion. Had the siblings been exposed to more stimulating or threatening situations than the older ones, they might have produced higher levels of hormones than the first born child. The younger babies might develop the ability to secrete more cortisol with the passage of time, age and experience than their elder ones. Older monkeys, while encountering other unfamiliar monkeys, might as well be frightened instead of exhibiting their virility. Order of birth cannot be ascertained on the rate of hormone production alone- there may be other parameters that influence it.

The author compares the study of the rhesus species with that of the humans, who are rather quite akin to monkeys as goes the biological structures and tries to educe similar patterns. The correlations might be logical to an extent, but they do not strengthen his argument. Return of a parent after an absence might be stimulating for one, while it may not affect the other person. Threatening or exciting situations vary from person to person, and a study pattern of how they react to a given circumstance would not predict their birth order correctly.

Studies have shown that there exist higher levels of cortisol hormones during pregnancy of first time in mother monkeys. We, however, cannot rule out problems that might have occurred during birth. Higher levels of hormones in mothers do not necessarily imply the same in their children. Birth complications might result in babies with the inability of producing enough hormones. Had there been more than one offspring at a time, there would have been chances for one baby inheriting the mother’s traits more than the others. A healthy monkey who has had offspring might give birth to a more competent child than the first-time mother monkey if her health conditions were worse.

The theory of hierarchy in rhesus monkeys on the basis of hormone stimulation may fail to establish strong grounds given that, there are alternatives enough to refute what the author had claimed. Moreover, a closer look into their behavioral patterns, inter-species interaction in addition to the proposed claim might shed some more light on the focus of the study.