State two points in favor of sex selection and two points against this process?
The pros of sex selection might be the benefit to a family or the benefit to society. A family that desires a specific sex would benefit from sex selection. Some families simply do not feel complete without a boy or without a girl. Many times these families will have more children than they desire in an attempt to conceive the sex they desire. Society could benefit from sex selection if the society became unbalanced. For instance, a society with mostly males would begin to suffer. Intentionally creating more females would benefit this society.
The cons of sex selection have to do with society as well. A society might be off balanced by sex selection. If too many couples desired the same sex, society would quickly become overloaded with either males or females. There is also the argument that sex selection is tampering with something that should be left to nature. Personally, I think humans are already far removed from natural selection, but there are valid scientific arguments against gender selection.
China has more men than women because female babies were "allowed" to die, were actively abandoned with death as a real possibility, or were abandoned, found, and taken to orphanages from which many were adopted by foreign families. My niece is a beautiful Chinese-American ten-year-old, born (probably - we don't know her exact date of birth) in late September of 2001. My brother and sister-in-law were caught in the unexpected turmoil and red-tape of trying to complete an international adoption in the wake of the 9/11 bombings and the radically intensified security that immediately followed. Fortunately for our family, they were able to complete the process and we are all blessed to have her in our midst.
Sex selection based on traditional, culturally-based desires leads to heartache (and worse) for families and children.
I have noticed that whenever I see a parent or parents with three children, the two oldest are usually both boys or both girls. The youngest child might be of either sex. This suggests to me that the parents had two children of the same sex and decided to roll the dice just one more time hoping to get a boy if they had two girls or a girl if they had two boys. But they stopped at three regardless of the outcome. If they succeeded in getting a child of the opposite sex they were satisfied; if they failed they gave up because they felt fated to have nothing but boys or nothing but girls, and they couldn't keep on rolling the dice forever. This is just my observation and deduction.
The only real reason for sex selection, in my opinion, is the selfish desires of the parents. There are people who, for whatever reasons, really want a child of one sex or the other. They feel that it is very important to them to have such a child. This seems to me to be a bit on the selfish side because there is really no reason to prefer one sex to the other. So I guess I'm saying that the pro is that you get to choose what you have, but that that seems inherently selfish.
The major argument against sex selection, I think, is that it tends to result in a disproportionate number of males in the population, as has in fact happened in China. A culture with too many men and too few women is likely to have all sorts of social problems and tensions. It will be fascinating to see how the Chinese deal with these problems in the coming decades.
Here's a pro - in societies where one gender is prized more, sex selection will have a long-term effect of slowing population growth. China's the one-child policy, coupled with sex selection, has led to a serious gender imbalance in that country; there are now many more men than women, which has contributed to lowering the birthrate even more.
One major point against is that sex selection is inherently gender biased, in the sense that it is deciding which sex has a right to live and which doesn't. Another would be that it could set a precedent for what amounts to eugenics, selecting only those with "good genes," a cultural construction in the first place, for birth.
Well if you take the big frontal cortex out of the equation then sexual selection is only pros and no cons because with any species that has sexual reproduction (excluding humans) the selection of a mate is based in the "genes" of that mate so the offspring have the best chances for survival. For example bower birds (Grounded) they build a bower (type of display) with anything they can find (males are dull and brown) and the female chooses them based on how good their bower is, so in this case the bird with the largest or best bower will get chosen. The reason this is good is that to build a bower not only takes co-ordination but it takes a strong bird (not only to build the bower but to eat less during the build for fear of other bower birds destroying their bower) so the choice is validated because the offspring will be stronger than other bower birds with higher intelligence to build a great bower to attract a mate and the cycle continues.
I do not think sex selection has its pros.
I do not agree with post 3 which undermines being selfish in the absolute sence. I know families having children of the same sex - my parents were amongst those. The number is large for being 'selfish', the family wanted a child of different sex and waiting for the right one to come the number of children went in to double digits where they stopped. Had there been a option to select the sex at that time, the number would have been much less. So sex selection may have help in some cases but generally it should be left to the nature in my opinion.