Science Says There Are More Than Two Genders

Pink for boys and blue for girls right? No? What are societal gender roles anyway and are they good or bad to keep in our everyday lives?

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Every Single Sex & Gender Term Explained
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The topic of this week's TestTube Plus is sex and gender. Trace began this series by explaining the terms involved in gender and sexuality. In this episode, Trace explains the science of gender identity. Future episodes will be discussing how sexuality and gender express themselves in non-human animals, and what a post-gender society might look like.

Gender is something we're taught from the moment we're born and although it's generally not discussed, to an extent it affects almost everything we do. A 2010 study of transgender people said they knew their identity by the time they were five years old.

Gender isn't sexual orientation: Every fetus begins in the womb as a female. The addition of the Y-chromosome makes the fetus acquire primary and secondary sexual characteristics. But things don't alway develop properly: sometimes both a fetus can get both male and female characteristics -- these are known as hermaphrodites or intersex.
Some animals are gynandromorphs: they have both male and female cells.

TestTube Plus is built for enthusiastic science fans seeking out comprehensive conversations on the geeky topics they love. Each week host Trace Dominguez probes deep to unearth the details, latest developments, and opinions on topics like aliens, genetics, and artificial intelligence. TestTube Plus is also available as a podcast--click here to subscribe!

Learn More:
Transsexual Differences Caught on Brain Scan (New Scientists)
"Differences in the brain's white matter that clash with a person's genetic sex may hold the key to identifying transsexual people before puberty. Doctors could use this information to make a case for delaying puberty to improve the success of a sex change later."

Confused by All the New Facebook Genders? Here's What They Mean (
"This month, Facebook started allowing users to self-identify as something other than male or female. Good. There may be some cynical ad-targeting motive at work, but as Facebook spokesman Will Hodges explains, "While to many this change may not mean much, for those it affects it means a great deal."

Assess the Relationship between Gender and Health (
"As with sex, gender can have a profound influence on health and well-being. Sometimes the impact of gender is direct and obvious. For example, ideals of female beauty in China led to the painful and disabling practice of foot binding."