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 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."
Write a response in which you discuss one or more alternative explanations that could rival the proposed explanation and explain how your explanation(s) can plausibly account for the facts presented in the argument.
The given letter explicates a study conducted for a group of monkeys which showed that birth order affects individuals' level of stimulation. The evidence it gives is first that firstborn infant monkeys develop twice the amount of homone cortisol as their younger siblings when exposed to stimulating situations. This is compared with firstborn humans who also manifest high levels of cortisol in commensurately stimulating situations. The study also states that first-time mother monkeys had more cortisol than others who already have experience with pregnancy. At the outset, all of this evidence seem to warrant the claim that there is a causation between birth order and individual stimulation, but this argument needs to be looked at more scrupulously. There are numerous unstated assumptions that need to be looked at in depth to qualify the validty of the claim.
First of all, the sample is not representative of the human population. Studying eighteen individuals of a certain group is too small a size to assert that the study's findings can be generalized to the whole population. Also, even though it is a widely acknowledged fact that primates and humans share a vast amount of similar traits, it does not guarantee that the given relationship manifests in the same way in humans. It could be possible that younger siblings show higher levels of cortisol in humans; there is no definite evidence showing that the causation in the monkeys can be applied to the humans.
Another flaw of the given evidence is that there is no information about people who are not firstborns. It is stated as a fact that firstborn humans show high levels of cortisol in stimulating situations, but we have no way of knowing how it compares to other siblings faced in the same situation. Perhaps humans vary from the reactions manifested in rhesus monkeys in that other younger siblings are more reactive to stimuating situations. It could also be possible that siblings show an equal level of cortisol. Unless data is provided on the difference between human siblings, the claim cannot decisively say that the given relationship exists.
Also, the fact that first-time expecting mothers have higher levels of cortisol does not warrant the relationship between birth order and child's cortisol level. The mother's high level of cortisol could just as easily not pass on to her child and retained in her body. There is no factual link that connects a mother's level of cortisol to her child's.
In conclusion, although the study may seem to show a valid claim, the findings could actually be spurious. There is not enough information to show that its assumptions are based on conclusive evidence.
Comments
Essay evaluation report
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argument 1 -- not OK
argument 2 -- not OK
argument 3 -- not OK
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sample arguments:
https://www.testbig.com/story/gre-argument-essay-topic-2-outline
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Attribute Value Ideal
Final score: ? out of 6
Category: Poor Excellent
No. of Grammatical Errors: 0 2
No. of Spelling Errors: 0 2
No. of Sentences: 20 15
No. of Words: 441 350
No. of Characters: 2211 1500
No. of Different Words: 194 200
Fourth Root of Number of Words: 4.583 4.7
Average Word Length: 5.014 4.6
Word Length SD: 2.731 2.4
No. of Words greater than 5 chars: 162 100
No. of Words greater than 6 chars: 124 80
No. of Words greater than 7 chars: 93 40
No. of Words greater than 8 chars: 49 20
Use of Passive Voice (%): 0 0
Avg. Sentence Length: 22.05 21.0
Sentence Length SD: 6.866 7.5
Use of Discourse Markers (%): 0.5 0.12
Sentence-Text Coherence: 0.327 0.35
Sentence-Para Coherence: 0.497 0.50
Sentence-Sentence Coherence: 0.129 0.07
Number of Paragraphs: 4 5
Transition Words or Phrases used:
actually, also, but, first, if, look, may, so, in conclusion, first of all, in the same way
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 24.0 19.6327345309 122% => OK
Auxiliary verbs: 9.0 12.9520958084 69% => OK
Conjunction : 6.0 11.1786427146 54% => More conjunction wanted.
Relative clauses : 23.0 13.6137724551 169% => OK
Pronoun: 34.0 28.8173652695 118% => OK
Preposition: 57.0 55.5748502994 103% => OK
Nominalization: 17.0 16.3942115768 104% => OK
Performance on vocabulary words:
No of characters: 2251.0 2260.96107784 100% => OK
No of words: 441.0 441.139720559 100% => OK
Chars per words: 5.10430839002 5.12650576532 100% => OK
Fourth root words length: 4.58257569496 4.56307096286 100% => OK
Word Length SD: 2.80171554366 2.78398813304 101% => OK
Unique words: 198.0 204.123752495 97% => OK
Unique words percentage: 0.448979591837 0.468620217663 96% => OK
syllable_count: 697.5 705.55239521 99% => OK
avg_syllables_per_word: 1.6 1.59920159681 100% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 5.0 4.96107784431 101% => OK
Article: 8.0 8.76447105788 91% => OK
Subordination: 3.0 2.70958083832 111% => OK
Conjunction: 2.0 1.67365269461 119% => OK
Preposition: 2.0 4.22255489022 47% => More preposition wanted as sentence beginning.
Performance on sentences:
How many sentences: 20.0 19.7664670659 101% => OK
Sentence length: 22.0 22.8473053892 96% => OK
Sentence length SD: 39.987373007 57.8364921388 69% => OK
Chars per sentence: 112.55 119.503703932 94% => OK
Words per sentence: 22.05 23.324526521 95% => OK
Discourse Markers: 4.55 5.70786347227 80% => OK
Paragraphs: 5.0 5.15768463074 97% => OK
Language errors: 0.0 5.25449101796 0% => OK
Sentences with positive sentiment : 5.0 8.20758483034 61% => OK
Sentences with negative sentiment : 5.0 6.88822355289 73% => OK
Sentences with neutral sentiment: 10.0 4.67664670659 214% => Less facts, knowledge or examples wanted.
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.188469476846 0.218282227539 86% => OK
Sentence topic coherence: 0.062533818519 0.0743258471296 84% => OK
Sentence topic coherence SD: 0.0654983115702 0.0701772020484 93% => OK
Paragraph topic coherence: 0.106445781294 0.128457276422 83% => OK
Paragraph topic coherence SD: 0.0394135242096 0.0628817314937 63% => OK
Essay readability:
automated_readability_index: 13.6 14.3799401198 95% => Automated_readability_index is low.
flesch_reading_ease: 49.15 48.3550499002 102% => OK
smog_index: 8.8 7.1628742515 123% => OK
flesch_kincaid_grade: 11.9 12.197005988 98% => OK
coleman_liau_index: 12.3 12.5979740519 98% => OK
dale_chall_readability_score: 8.45 8.32208582834 102% => OK
difficult_words: 104.0 98.500998004 106% => OK
linsear_write_formula: 11.0 12.3882235529 89% => OK
gunning_fog: 10.8 11.1389221557 97% => OK
text_standard: 11.0 11.9071856287 92% => OK
What are above readability scores?
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Rates: 66.67 out of 100
Scores by essay e-grader: 4.0 Out of 6
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Note: the e-grader does NOT examine the meaning of words and ideas. VIP users will receive further evaluations by advanced module of e-grader and human graders.