🌈Lesbian Birth Order Effect

☆☆☆☆ Christine Ablaza et al., 2022 ☆☆☆☆

“Our analyses yield robust evidence of a birth order effect on both male and female homosexuality. Additionally, we find that individuals’ birth order affects the probability of entering a same-sex union, regardless of the sex of older siblings.

Ablaza, C., Kabátek, J., & Perales, F. (2021). Are sibship characteristics predictive of same sex marriage? An examination of fraternal birth order and female fecundity effects in population-level administrative data from the Netherlands. The Journal of Sex Research, 1–13.

Innate vs. Choice

“The implications… are far-reaching.” — Why?

Answer: Because some people are more supportive of marriage equality due to an understanding that sexuality is associated with genetics/DNA. From their perspective, if LG individuals don’t have a choice in who they love, then they are content with same-sex marriage.

Bisexual Child

Original Birth Order Data

Age of Awareness of Sexuality: Bisexual Edition

My Data

An analysis of the bisexual subjects from my (2014) study indicated that bisexual women (n = 80) in my sample became aware of their sexuality around age 14.2 & bisexual men (n = 20) age 14.05.

⏳At What Age Did You Know? (Tara Pond’s Data)

“Most bisexual women became aware at 17.4 years of age & came out to someone at 20.9 years of age” (Pond, 2020).

Bisexual Sexual Debut

“The average age that bisexual respondents had sex for the first time (16.5 years old) was similar to ages reported with heterosexual samples, including in Aotearoa/New Zealand (Cavazos-Rehg et al., 2009; Lowry et al., 2017; Psutka et al., 2012)” (Tara Pond, 2020).


Contraception & Testosterone 💊

Casto et al., 2021: “Among female university athletes, OC users had significantly lower testosterone levels than non-users due to the testosterone suppressing effects of OC use” (Kathleen Casto et al., 2021).

What is Sex? — Oxford, J., & Duncan, A. R. (2021)

Lesbians and gay men think differently about what constitutes sex, such that lesbians consider genital stimulation to be more constitutive of sex than heterosexuals do (Horowitz & Spicer, 2013) and gay men consider anal intercourse to be the behavior that constitutes sex the most (Hill et al., 2010).

Cohabitation — Balsam et al., 2017

Women are socialized to place greater emphasis on intimate relationships and have higher expectations for relationship quality than men. For example, women in same-sex relationships are more likely to cohabitate (Rosenfeld, 2014), are about twice as likely as men to enter into legal unions (Rosenfeld, 2014; Solomon et al., 2004), and wait a shorter period to legalize their relationship than do men (Rothblum et al., 2008).

For gay men → 40% of the male–male couples had an agreement that sex outside their relationship was acceptable under some circumstances, something that was true for only 6% of heterosexual & female–female couples (Solomon et al., 2005).

Thus, non-monogamy was not a predictor of relationship dissolution for men in same-sex relationships, consistent with other research on gay men (Bricker & Horne, 2007; Parsons, Starks, Gamarel, & Grov, 2012) in which non-monogamy is not a predictor of relationship satisfaction.



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Dr. Jarryd Willis PhD

Dr. Jarryd Willis PhD

I'm passionate about making a tangible difference in the lives of others, & that's something I have the opportunity to do a professor & researcher.