Comment ça se fait que l'orientation hétérosexuelle soit si majoritaire partout dans le monde, et est-ce que ça change vraiment au fil du temps et des cultures ?
Demographics

In their 2016 literature review, Bailey et al. stated that they "expect that in all cultures the vast majority of individuals are sexually predisposed exclusively to the other sex (i.e., heterosexual)" and that there is no persuasive evidence that the demographics of sexual orientation have varied much across time or place. Heterosexual activity between only one male and one female is by far the most common type of sociosexual activity.

According to several major studies, 89% to 98% of people have had only heterosexual contact within their lifetime; but this percentage falls to 79–84% when either or both same-sex attraction and behavior are reported.

A 1992 study reported that 93.9% of males in Britain have only had heterosexual experience, while in France the number was reported at 95.9%. According to a 2008 poll, 85% of Britons have only opposite-sex sexual contact while 94% of Britons identify themselves as heterosexual. Similarly, a survey by the UK Office for National Statistics (ONS) in 2010 found that 95% of Britons identified as heterosexual, 1.5% of Britons identified themselves as homosexual or bisexual, and the last 3.5% gave more vague answers such as "don't know", "other", or did not respond to the question. In the United States, according to a Williams Institute report in April 2011, 96% or approximately 250 million of the adult population are heterosexual.

An October 2012 Gallup poll provided unprecedented demographic information about those who identify as heterosexual, arriving at the conclusion that 96.6%, with a margin of error of ±1%, of all U.S. adults identify as heterosexual. The Gallup results show:

In a 2015 YouGov survey of 1,000 adults of the United States, 89% of the sample identified as heterosexual, 4% as homosexual (2% as homosexual male and 2% as homosexual female) and 4% as bisexual (of either sex).

Bailey et al., in their 2016 review, stated that in recent Western surveys, about 93% of men and 87% of women identify as completely heterosexual, and about 4% of men and 10% of women as mostly heterosexual.
Ensemble de la bisexualité et de l'hétérosexualité, l'homosexualité est l'une des trois principales catégories d'orientation sexuelle au sein du continuum hétérosexuel-homosexuel. Les scientifiques ne connaissent pas encore la cause exacte de l'orientation sexuelle, mais ils émettent l'hypothèse qu'elle est due à une interaction complexe de facteurs génétiques, hormonaux et environnementaux et ne la considèrent pas comme un choix. Bien qu'aucune théorie unique sur la cause de l'orientation sexuelle n'ait encore obtenu un soutien généralisé, les scientifiques privilégient les théories fondées sur la biologie. Il existe beaucoup plus de preuves soutenant des causes non sociales et biologiques de l'orientation sexuelle que des causes sociales, en particulier chez les hommes. Il n'existe aucune preuve substantielle suggérant que l'éducation ou les expériences de la petite enfance jouent un rôle en ce qui concerne l'orientation sexuelle. Bien que certains pensent que l'activité homosexuelle est contre nature, la recherche scientifique montre que l'homosexualité est une variation normale et naturelle de la sexualité humaine et n'est pas en soi une source d'effets psychologiques négatifs. Il n'existe pas suffisamment de preuves pour étayer l'utilisation d'interventions psychologiques visant à modifier l'orientation sexuelle.
### Query ###
Comment ça se fait que l'orientation hétérosexuelle soit si majoritaire partout dans le monde, et est-ce que ça change vraiment au fil du temps et des cultures ?

### Main Text ###
Demographics

In their 2016 literature review, Bailey et al. stated that they "expect that in all cultures the vast majority of individuals are sexually predisposed exclusively to the other sex (i.e., heterosexual)" and that there is no persuasive evidence that the demographics of sexual orientation have varied much across time or place. Heterosexual activity between only one male and one female is by far the most common type of sociosexual activity.

According to several major studies, 89% to 98% of people have had only heterosexual contact within their lifetime; but this percentage falls to 79–84% when either or both same-sex attraction and behavior are reported.

A 1992 study reported that 93.9% of males in Britain have only had heterosexual experience, while in France the number was reported at 95.9%. According to a 2008 poll, 85% of Britons have only opposite-sex sexual contact while 94% of Britons identify themselves as heterosexual. Similarly, a survey by the UK Office for National Statistics (ONS) in 2010 found that 95% of Britons identified as heterosexual, 1.5% of Britons identified themselves as homosexual or bisexual, and the last 3.5% gave more vague answers such as "don't know", "other", or did not respond to the question. In the United States, according to a Williams Institute report in April 2011, 96% or approximately 250 million of the adult population are heterosexual.

An October 2012 Gallup poll provided unprecedented demographic information about those who identify as heterosexual, arriving at the conclusion that 96.6%, with a margin of error of ±1%, of all U.S. adults identify as heterosexual. The Gallup results show:

In a 2015 YouGov survey of 1,000 adults of the United States, 89% of the sample identified as heterosexual, 4% as homosexual (2% as homosexual male and 2% as homosexual female) and 4% as bisexual (of either sex).

Bailey et al., in their 2016 review, stated that in recent Western surveys, about 93% of men and 87% of women identify as completely heterosexual, and about 4% of men and 10% of women as mostly heterosexual.

### Supplementary Text ###
Ensemble de la bisexualité et de l'hétérosexualité, l'homosexualité est l'une des trois principales catégories d'orientation sexuelle au sein du continuum hétérosexuel-homosexuel. Les scientifiques ne connaissent pas encore la cause exacte de l'orientation sexuelle, mais ils émettent l'hypothèse qu'elle est due à une interaction complexe de facteurs génétiques, hormonaux et environnementaux et ne la considèrent pas comme un choix. Bien qu'aucune théorie unique sur la cause de l'orientation sexuelle n'ait encore obtenu un soutien généralisé, les scientifiques privilégient les théories fondées sur la biologie. Il existe beaucoup plus de preuves soutenant des causes non sociales et biologiques de l'orientation sexuelle que des causes sociales, en particulier chez les hommes. Il n'existe aucune preuve substantielle suggérant que l'éducation ou les expériences de la petite enfance jouent un rôle en ce qui concerne l'orientation sexuelle. Bien que certains pensent que l'activité homosexuelle est contre nature, la recherche scientifique montre que l'homosexualité est une variation normale et naturelle de la sexualité humaine et n'est pas en soi une source d'effets psychologiques négatifs. Il n'existe pas suffisamment de preuves pour étayer l'utilisation d'interventions psychologiques visant à modifier l'orientation sexuelle.

### Draft ###

Query: "Comment ça se fait que l'orientation hétérosexuelle soit si majoritaire partout dans le monde" + temporal/cultural variation question.

Translation nuance: "majoritaire partout" - absolute majority vs universal pattern? User implies heteronormativity as global norm, seeks explanation + evidence of change.

Task type: Information synthesis + causal analysis. Not simple retrieval.

### 1. Initial Framing

Query assumes heterosexuality as "global norm" - needs verification. ● High confidence this is accurate for sexual behavior patterns, ◐ partial for self-identification categories (cultural reporting variance).

User also asks about temporal/cultural stability - implies possible change over time/place. This requires longitudinal data + cross-cultural comparison.

### 2. Demographic Evidence Retrieval

Global heterosexual majority: Need recent surveys...

⟨H≈0.2⟩ Standard demographic studies consistently show 85-95% heterosexual identification across cultures. US data (Gallup 2012): 96.6%. UK ONS: 95%. Recent European surveys similar patterns.

But wait - distinction between behavior vs identification? 
Lifetime heterosexual behavior studies: 89-98% range globally. 
→ Suggests gap between private behavior and public identification.

Geographic variation? ◐ Limited data across all regions. Western surveys more consistent.

### 3. Evolutionary/Biological Foundation

Why such stability? Need evolutionary perspective...

⟨H≈1⟩ Reproductive strategy considerations. Heterosexuality as primary mating pattern for species reproduction. Most human societies historically polygynous - heterosexual couples as primary reproductive units. Cultural evolution reinforcing biological tendencies?

Bailey 2016 review → "vast majority sexually predisposed exclusively to opposite sex" across cultures. 

But evolutionary explanations insufficient alone - need social/cultural factors.

### 4. Temporal Variation Analysis  

User asks about change over time. 

⟨H≈1.2⟩ Historical patterns... Victorian morality, pre-modern societies, how measured/reported? Kinsey 1948-53 showed 93.9% heterosexual behavior for American men. More recent surveys suggest slight decline but still majority.

Temporal stability remarkable given cultural change acceleration.

! Key insight: distinction between demographic reality vs cultural visibility of minorities.

### 5. Cross-Cultural Patterns

Heterosexual majority seems universal but...

⚠ Reporting bias potential. Many societies don't systematically survey sexual orientation. 
? How do traditional/authoritarian societies report sexual minorities?
? Rural vs urban differences within cultures?

◐ Incomplete data globally, especially developing nations.

### 6. Stability Mechanisms

Why so persistent? Multiple factors:

1. **Biological substrate** → reproductive advantages of heterosexual pair-bonding
2. **Social reinforcement** → cultural institutions favor heterosexual norms  
3. **Self-reinforcing demographics** → heterosexual reproduction maintains majority
4. **Measurement consistency** → same methodologies across decades

### 7. Minority Populations Context

Heterosexual majority doesn't negate significant minority populations.

Recent surveys: 4-10% bisexual identification, 1-2% homosexual.
→ Still substantial populations, just minority of total.

Cultural visibility increasing but demographic ratios remain stable.

### 8. Limitations & Caveats

∴ Heterosexual majority pattern appears robust across time/culture, but:

⚠ **Data limitations**: Survey methodology varies, cultural reporting biases
⚠ **Temporal granularity**: Limited longitudinal studies  
⚠ **Geographic sampling**: Western-centric data, limited global coverage
⚠ **Measurement challenges**: Self-reporting vs behavioral patterns

◐ **Conclusion**: Strong evidence for heterosexual majority stability, but mechanisms complex. Interaction between biological predispositions, cultural reinforcement, and demographic processes creates persistent pattern. Minorities exist and may be increasing proportionally, but foundational heterosexual majority appears both biologically and socially reinforced.

※ Need better global data for complete answer. Current evidence suggests remarkable stability despite cultural change.

### Answer###
L'hétérosexualité constitue effectivement la majorité écrasante à travers le monde. Plusieurs études récentes montrent que 89% à 98% des personnes ont eu uniquement des contacts hétérosexuels dans leur vie, et cette proportion atteint 93-96% lorsque l'on considère uniquement l'identification personnelle comme hétérosexuelle.

Cette dominance s'observe partout : aux États-Unis, 96,6% des adultes se déclarent hétérosexuels selon une étude Gallup de 2012, tandis qu'au Royaume-Uni, 94% des personnes se considèrent comme hétérosexuelles. Des données similaires émergent d'autres pays européens.

Concernant votre question sur l'évolution temporelle, les recherches indiquent qu'il existe peu de preuves suggérant que la démographie de l'orientation sexuelle ait beaucoup varié au fil du temps ou selon les lieux. Les scientifiques considèrent que la grande majorité des individus est sexuellement prédisposée exclusivement à l'autre sexe dans toutes les cultures.

Cependant, il convient de noter qu'environ 4% des hommes et 10% des femmes dans les enquêtes récentes se déclarent majoritairement hétérosexuels, et une minorité significative - environ 4% aux États-Unis - s'identifie comme bisexuelle ou homosexuelle.

Les causes de cette distribution démographique semblent résider dans une interaction complexe de facteurs génétiques, hormonaux et environnementaux qui favorisent l'orientation hétérosexuelle comme configuration la plus répandue, bien que les mécanismes précis restent encore partiellement incompris.