Why do some families have more male or female offspring?

  1. This is one of the questions in my on-line psychology course I'm taking.

    I can't seem to find the answer in my text.

    The full question is:

    State why some families have more male or female offspring generation after generation.

    It's in the chapter on chromosomes, genes, and the like. Any help would be appreciated.

    Thanks all!!!!
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  2. 4 Comments

  3. by   fourblessings
    Well, being a mom with 3 girls, we definately have more female offspring! I think genes definately come into play,also....some men might have more xx sperm, or visa versa, they have more xy sperm. But a thing I have heard of, however, is how close to ovulation you have intercourse predicts the sex, or the more chance of having a XY or XX. Having intercourse 3-4 days away from ovulation can increase having a female, because female sperms live longer, thus increase their chances of reaching the egg, and the male sperms die faster. Having intercourse closer to ovulation, like a day before or on ovulation day, increases your chance for a male, because male sperms are faster to reach the egg than female sperm (but they die off quicker than female sperms, so it needs to be around ovulation day). Many people swear on this theory, there is a book called "shettle's method" that explains it more in detail.

    Good luck with your class!
  4. by   manna
    Interesting question!

    Incidentally, my in-laws had all boys, and my husband and I have all boys too!
  5. by   ChrisA
    when you say "generation after generation", is this traced through the male line or the female line?

    If there are more males than females, there could be a generalized malformed X chromosome in the females, such that roughtly 50% of female zygotes prove not to be viable. Now, this sort of thing isn't really down to the way the homologous pairs divide during the first stage of meiosis, so the chances that there's a greater number of x or y sperm after meiosis isn't likely, especially with the millions of sperm produced. Remember that sex is determined by the father. The fact that fourblessings raises, about how Y-carrier sperm die sooner than X-carriers, is a really good one, but how likely is it that generation after generation were having sex during one of those windows or another? It's an interesting question. It can't really be answered without a pedigree.

    I would look either to deformations in the sex chromosomes generally, or issues with the viability of sperm.
  6. by   UGAmomX3
    I'm not going to even try to get technical, but in our family, we don't even think about buying anything pink. I have three boys..quit before I had a basketball team. The father of the boys had one sibling, a brother. This brother has one child, a boy. Their father was one of five kids, three boys and two girls, but the girls had a different father. The next generation back was all boys also. So, at least in our case, it doesn't matter about the mother. We're just doomed (or blessed,as the case may be) to produce male children if we get tangled up with this family. Personally, as much as I wanted a little girl, somebody knew I would do better with boys. And besides, now I get daughters by marriage, (just got one a month ago) and I didn't even have to go through potty training or multiplication tables! Mary

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