Birth Order, Brothers, and Homosexuality

Written by dad - 4 Comments

Interesting. My lovely and talented wife pointed out to me that a recent study out of Canada has established a link between homosexuality and “fraternal birth order” — i.e., how many older brothers a male has. While numerous previous studies have shown that a man’s sexual orientation can be influenced by the number of older brothers that he has, it has remained unclear whether or not this is simply an environmental effect of being reared with brothers, or if there is some underlying (but unknown) biological mechanism at work. Well…

It now seems that prenatal factors are responsible. Indeed, whether or not boys were raised together, the number of biological brothers that an individual has influences sexual orientation, whereas an increase in the number of non-biological brothers in the household had no effect. Of course, this is only a tiny part of the story… According to the study, a woman’s first son has a 3% chance of being homosexual, whereas her fourth son has a 6% chance. Thus, while the likelihood doubles, it’s still a rather subtle effect.

The leading explanation for this phenomenon is the ‘maternal immunization hypothesis,’ in which a mother’s body creates antibodies against foreign male proteins. These antibodies can increase in the mother with each successive male baby, and it’s believe that they can affect a baby’s brain development and hormonal levels.

As the third of three brothers, I can honestly say that haven’t seen this effect in action. Then again, I’m the father of four young boys, so only time will tell.

[Source: ABCNews.com]

Published on July 7th, 2006 - 4 Comments
Filed under: Health
digg this - stumble it - save to del.icio.us

Related articles...

If you found this article useful, please sign up to receive free e-mail updates:

You will receive only the daily updates, and can unsubscribe at anytime.

Comments (scroll down to add your own):

  1. I would not overly worry about it.

    Comment by Blaine Moore — Jul 7th 2006 @ 8:36 am
  2. Oh, I’m not worried… Just thought that it was interesting.

    Comment by dad — Jul 7th 2006 @ 9:00 am
  3. So ever thought of a fifth child?

    Comment by Livingalmostlarge — Jul 8th 2007 @ 10:50 pm
  4. Ummm… No. As fisherman like to say, we’ve caught our limit.

    Comment by dad — Jul 10th 2007 @ 10:40 am

Sorry, the comment form is closed at this time.

Get free updates...

Articles via e-mail:

Search this site...

Sponsors...

Popular topics...

Recent articles...

Recent comments...

  • Nan: Believe me when I tell you that allowing disrespect from a child creates...
  • Misty: Hello all… It has been a few years since I last posted and...
  • heather: This is for lovely Maria, who obviously doesn`t understand. I will...
  • Brittney: My son is just 3 and a half years old and was recently diagnosed...
  • Mary Gulledge: Yes they do personalize the autographs…I got one for my...
  • Brooke: Thanks Amy for responding. I have decided to wait on the Intuniv for...
  • Amy: Hi Brooke! My son, now 9 yrs old, has been on Intuniv for 2 and a half...
  • Brooke: My daughter, 10 years old, is in the fifth grade. She is struggling...

Most talked about...