We actually know a couple sets of brothers – and even one set of twins, who have a queer sister – who are gay. And no, they aren't characters in some Bel Ami flic. Given sexuality's link to genetics, we've often wondered whether parents who give birth to one gay chlid are likely to give birth to, well, more than one gay child. And where does child rearing come into play? Scientists, it turns out, are quite interested in the links as well.

Researchers at a handful of Chicago-area universities are looking to explore the connection between gender-bending childhoods (i.e. boys who exhibit feminine qualities during childhood) by linking childhood experiences among sets of gay brothers.

In order to explore these observations further, researchers from the Evanston Northwestern Healthcare Research Institute, Northwestern University, University of Chicago, and University of Illinois at Chicago are seeking gay men with at least one living gay brother to share recollections of their childhood behaviors such as play activities, relationships with others, and so on.

People in the study will provide a sample of blood (the sample is used to extract DNA for the genetic part of the research study) but researchers are not studying other aspects of the blood, such as a person’s HIV status.

The brother volunteers will also complete questionnaires about their sexual interests and experiences, memories of their childhood and adult gender related behavior, demographic characteristics, health and medical history, and personal and family history.

If you've got a gay brother and are willing to be poked and prodded for the sake of science, you're welcome to register for the study at the aptly named GayBros.com. Just make sure that after you donate blood, they give you a protein shake instead of a Juicy Juice.

(And yes, we know the Carlson Twins, pictured, aren't gay. But we're sure someone out there will welcome their bodily fluids.)

Oh, brother! Study seeks gay siblings... [GayHealth]