3.3b Gender and Sexual Orientation

LT 3.3-10: Explain what research has taught us about sexual orientation.
LT 3.3-11: Explain the biological research that helps us understand sexual orientation.

Sexual Orientation (APA, 2015): A person's sexual and emotional attraction to others, along with related behavior and social affiliation.
Directed Sexual Interest: Can include heterosexuality, homosexuality, bisexuality, asexuality, among others.
**Cultural Attitudes: ** Varies widely; acceptance is increasing globally. Examples: 94% of Swedes accept homosexuality vs. 7% of Nigerians.

Statistics on Same-Sex Attraction: 3-4% of men and 2% of women identify as exclusively same-sex oriented; higher percentages found in anonymous surveys.
- California vs. Mississippi: 3% vs. 1% identifying as homosexual on social media platforms.
Impact of Marginalization: Higher levels of stress, depression, and suicide rates among those who are gay, leading to challenges in self-acceptance.
Psychological Viewpoint: Sexual orientation is not willfully chosen or changeable.

Kinsey Institute Research: Found no significant differences in parenting, childhood experiences, peer relationships that could account for different sexual orientations.

Brain Differences

Simon Levay's Research: Identified that the hypothalamus tends to be larger in straight males than in gay males, indicating biological differences manifest early in life.
“Gay men appear, on average, more “female typical” in the brain pattern responses and gay women are somewhat more “male typical”
Cognitive Abilities: Different cognitive abilities observed, e.g., straight men outperform straight women and gay men in some spatial tasks, while straight women and gay men excel in others.

Genetic Influences

Approximately 1/3 of variation in sexual orientation is genetic, with a higher correlation of same-sex orientation among identical twins than fraternal twins.
- Research Example: Altering a single gene in fruit flies can change their sexual orientation behaviors.
- Kin selection is the idea that animals (including humans) help their family members because they share genes. By supporting relatives in having babies, they ensure that similar genes continue to exist in the next generations. So, even if they don't have many offspring themselves, helping family can still pass on their shared traits.
- The Fertile Female Theory states that males tend to choose females who are healthy and can have many babies. This idea is related to kin selection, meaning animals might prefer helping relatives or mating with those who can produce strong offspring. By focusing on fertile females, males increase their chances of passing on their genes. This theory illustrates how natural selection affects mating choices, promoting the continuation of family lines.

Prenatal Influences

Factors such as hormonal exposure (e.g., testosterone) and maternal immune response can affect sexual orientation. The older-brother effect suggests that men with multiple older biological brothers are more likely to be gay due to maternal immune-system reactions.

Table 3.3-1 Highlights:
- Differences noted in spatial abilities, finger lengths, auditory system development, binary preferences, and more between gay and straight individuals.
- Overall findings suggest that the spectrum of sexual orientation is accompanied by biological and behavioral traits, indicating a complex interplay of genetic, brain, and prenatal influences.

Research into sexual orientation encompasses psychological definitions, societal attitudes, and biological influences collectively contributing to an understanding of human sexuality and behavior.

What constitutes sexual orientation?
How do prenatal hormones influence sexual orientation?
Reflect on how your understanding of sexual orientation might influence your interactions with others.