#46 – Homosexuality: A Twin Thing

Research has shown that sexual orientation is greatly determined by genetics. We also know that identical twins share 100% of their genetic material. Then how is it possible that only about 30% of all identical twins have the same sexual orientation as their co-twin?

In Episode 46, Dr. Zhana and Joe speak with Dr. Gerulf Rieger about his research on identical twins with discordant sexual orientation. Dr. Rieger tests whether childhood gender non-conformity, genital arousal patterns, and finger length ratio–all known indicators of adult homo- or heterosexuality–also differ among identical twins who differ in self-reported sexual orientation. And sure enough, they do! (I.e., they’re not lying.) So if it’s not genetics, where is this difference in sexual orientation coming from? Tune in to find out more!

You can read the full studies discussed in the episode:

Gender Non-Conformity

Finger Length Ratio

Sexual Arousal Patterns

About our Guest

Gerulf Rieger obtained a MSc in Biological Anthropology from the University of Zurich in Switzerland and a PhD in Personality Psychology from Northwestern University, Evanston, Illinois. Gerulf had a teaching position at Northwestern University and was a research fellow in the Department of Human Development at Cornell University before joining the Psychology Department at the University of Essex.

You can visit his website here.

Don’t Miss This Week’s Foreplay…

Everyone is talking about this New York Times article. The Trump administration is trying their hardest to define gender strictly based on genitals. Consequently, erasing trans folks by defining them out of existence. This attempted claim in not only terrifying and dangerous for the trans community but is also scientifically inaccurate. This is not the definition of gender, or sex. Sex is defined by a number of things only one of which is genitals at birth. Even if sex is the only thing the administration were trying to define it is far too complicated to reduce to external genitalia. Tune in to find out more and read the full article here.

Before Next Time…

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