argument53

魏玛竹林UID: 2201594

TOPIC: ARGUM - Thirteen years ago, researchers studied a group of 25 infants who showed signs of mild distress when exposed to unfamiliar stimuli such as an unusual odor or a tape recording of an unknown voice. They discovered that these infants were more likely than other infants to have been conceived in early autumn, a time when their mothers' production of melatonin-a hormone known to affect some brain functions-would naturally increase in response to decreased daylight. In a follow-up study conducted earlier this year, more than half of these children-now teenagers-who had shown signs of distress identified themselves as shy. Clearly, increased levels of melatonin before birth cause shyness during infancy and this shyness continues into later lifuture.

The author claimed that the increased levels of melatonin before birth cause shyness during infancy and this shyness continues into later life, because two separated surveys on a group of 25 children which conducted at their infancy time and their teenage time thirteen years later. I found this argument is not cogent after examining it from some other aspects.
To begin with, the author presumptuously acknowledges that melatonin has something to do with the shyness, which is not necessarily the case. The only thing about melatonin's effect we know from the argument is that it affects some brain functions. We even do not know the affected brain means the mother's brain or the child's brain. Even if the child's brain did affect by melatonin, what is the specific effect? Maybe it cause the child thought slow or careless. Then the shyness may have nothing to do with melatonin. To make his claim convincing, the author has to prove the relationship between melatonin and the shyness.
If we turn our attention to the first survey, we will easily find some vital flaws in it. A group of 25 infants is too small to be representative and without a controlled group, the study is not convincing. Maybe the 25 of them are all in a poor health, which is the real reason for distress.  Or maybe their distress is quite common among their peers who have the normal amount of melatonin before birth because of simple human nature rather than shyness. Without rule out the other factors, the author cannot come to the conclusion that increased levels of melatonin before birth cause shyness during infancy.
The second survey is more groundless. First of all, without considering the experience of these children during the thirteen years, which contributes a lot to their personalities, the author attributes their shyness to melatonin. It is highly probable that the shyness is caused by a lonely childhood or some certain obstacles, such as witness a car accident, lose a favorite relative. In a word, there are too many causes for a teenager’s shyness. Secondly, the shyness is just identified by the children themselves, which is a too subjective judgment to be confirmative. The author has to provide more forceful evidence to proof that the shyness continues in their later life.
To sum up, the argument based on a unsettled assumption and two careless survey. It is not well-reasoned.