What determines a human's sexual attraction?
Human sexual attraction is determined by heritable evolutionary behavior (i.e. genetics) and environmentally imprinted behavior (i.e. upbringing) for sexual mate selection.
What is heritable evolutionary behavior for human sexual mate selection?
Heritable evolutionary behavior for human sexual mate selection is defined by a human's genetics.
These genetics ensure a human is attracted to phenotypic traits characteristic of humans.
You can extrapolate this logic to understand how a human's parents' genetics for sexual mate preferences may influence the human's sexual mate preferences.
Here is the scientific data.
Studies on twins at a large-scale prove that ~20% of a human's mate selection preferences are heritable [1].
So, genetics influence ~20% of a human's mate selection preferences (for physical and social traits) [1].
These genetics are inherited from a human's parents via DNA.
Here are examples
What is the Major Histocompatibility Complex (MHC)?
"The major histocompatibility complex (MHC) is a large locus on vertebrate DNA containing a set of closely linked polymorphic genes that code for cell surface proteins essential for the adaptive immune system."
— Wikipedia [2]
The Major Histocompatibility Complex (MHC) gene is an example of a significant genetic trait in the context of sexual mate selection [3].
Studies show a woman’s immune system seeks out Major Histocompatibility Complex (MHC) gene dissimilarity in sexual mates to maximize offspring immunity and the result is the rejection of men with familial genetic traits [3].
What is The Fisherian Runaway Feedback Loop?
The Fisherian Feedback Loop refers to a process in sexual selection where female preferences for certain male traits lead to the exaggeration of those traits over generations.
— referenced by Wikipedia / Chegg / Connallon & Hall [4, 5]
The Fisherian Runaway Feedback Loop ensures that preferred traits become more desired over time [4, 5]. The loop prevents attraction templates from being mixed up among sexes (i.e. men and women) over generations which would result in an evolutionary stalemate.
The Fisherian Runaway Feedback Loop results in sexual dimorphism in humans.
Here is a simplified example.
Male traits and respective female preferences for the traits are linked together on the same chromosome.
Suppose a woman has sex via Female Sexual Mate Selection:
- Her sons inherit the physical male trait which makes them more attractive to the next generation of women.
- Her daughters inherit the specific genetic preference for that exact male trait.
The positive feedback loop which results from this genetic link ensures
- preferred male traits do not get mixed into female traits.
- preferred male traits become universally desired, exaggerated, and locked into the population's evolutionary template.
However, this example is extremely simplified because the reality is the daughter can inherit her sexual preference gene from either
- the mother's active preference (as indicated by the example)
- or
- the father's hidden preference.
You can view the following tables for a breakdown of this simple example compared to reality, alongside real-world biological constraints.
| Metric / Attribute | The Simplistic Example | The Reality | Scientific / Empirical Caveat |
|---|---|---|---|
| Daughter's Preference Source | Inherited solely from the mother. | Her preference is a shuffled mix of the mother's active preference and the father's hidden preference genes. | High genetic shuffling (recombination) bounds absolute preference consistency [6]. |
| Son's Physical Trait Source | Inherited solely from the father. | His physical trait is a shuffled mix of the father's physical trait and the mother's hidden physical trait genes. | Physical ornaments are highly polygenic and heavily reliant on overall genetic health [6]. |
| Trait Transmission | Linear and predictable (like a straight line). | Omnidirectional and scrambled every generation (like a web). | Epistasis and changing survival costs generate chaotic, cyclic evolutionary patterns [6]. |
| Population Outcome | Infinitely runaway, exploding traits. | Kept in a state of chaotic balance across the population. | Counter-selection limits: Natural selection penalizes extreme traits when physical survival costs become too high [7]. |
| Mating Vector | How the Father Got the Gene | State inside the Father | Outcome in the Daughter | Real-World Fitness Advantage |
|---|---|---|---|---|
| Paternal Grandmother | Passed actively to the grandfather, who passed it silently to the father. | Silent / Unexpressed | Can become Active (Daughter matches her grandmother's taste). | Promotes underlying population-wide genetic variance preservation [6]. |
| Maternal Grandmother | Passed directly and actively from the mother to the father. | Silent / Unexpressed | Can become Active (Daughter matches her paternal grandmother's taste). | Inbreeding avoidance mechanism by continuously shifting dynamic trait baselines [2]. |
How does coercion affect the genetic human sexual mate preference?
Coercion (e.g., via provisional or forceful means) affects heritable evolutionary behavior for human sexual mate selection (i.e. genetics) by breaking the Fisherian Feedback Loop [8, 9].
- The resulting offspring are forced to inherit the traits of a male the mother did not select.
- Suppose a woman who prefers purple men is forced to mate with a green man.
- Under Female Sexual Mate Selection (where the woman mates with a purple man): The child inherits purple skin and genes which prefer men with purple skin.
- Under Coercion: The child could inherit the mother's preference for men with purple skin, but the father's physical genes for green skin.
- So, the "loop" is destroyed.
- The population shifts toward an evolutionary arms race instead of evolving more sexually-desired male traits because traits which women prefer are less important for reproduction than genes related to coercive reproduction [8, 9].
- Men evolve more traits for provisional coercion, while women more traits for resistance to coercion to preserve the ability to choose mates in future generations [8, 9]. This would create a state of intense sexual conflict where the sexes use opposite-sex mates as extended phenotypes to maximize asymmetric investments [10].
You can view the following table for a breakdown of this selective shift.
| Genetic Event | Under Voluntary Choice (Loop Works) | Under Coercion (Loop Breaks) | Evolutionary Arms Race / Conflict Mechanism |
|---|---|---|---|
| How are genes aligned? | Sexual trait preference and physical traits align perfectly in the offspring. | Sexual trait preference and physical traits are mismatched in the offspring. | Mismatches drive behavioral and psychological defenses like mate-guarding, jealousy, and deception [10]. |
| What determines how the next generation is selected? | Sexual Selection driven by attraction and aesthetics (FSM). | Natural Selection / Force driven by physical dominance (PSC, FSC). | Asymmetry shifts selection pressures away from ornament display and toward competitive dominance traits [11]. |
| What is the trend of the trait in the population? | The preferred physical trait is rapidly exaggerated across generations. | The preferred physical trait stagnates or is randomized. | Male strategies fragment between low-investment (coercive/short-term) and high-investment (provisional) behaviors [11]. |
You can view the following table for a breakdown of how the loop is broken even when the physical and sexual preference traits align accidentally after a coercive procreation.
| What happens in a working Fisherian Loop? | What happens when there is Coercion with Accidental Physical and Sexual Preference Trait Alignment? | |
|---|---|---|
| at the Individual Level | Child inherits active preference + matching physical trait. | Child might inherit hidden preference + matching physical trait by chance. |
| at the Population Level | Uniform, directional pressure pushes the whole species toward an extreme. | Fragmented, randomized pressure that stalls out any single trend. |
| What is the outcome? | Exaggerated or specialized traits (like a peacock's tail). | Average, baseline stabilization or a shift toward traits which assist coercive reproduction. |
So, there can exist scenarios where there is a preference for males who don't exist, and those women don't find any man attractive.
| Co-Evolving Population (Normal Loop) | Coercive Population (The Mismatch) | |
|---|---|---|
| Male Phenotype | Matches the average female preference. | Matches the mechanics of physical dominance/force [10]. |
| Female Genotype | Codes for preferences that exist in the real world. | Codes for "phantom preferences" from a previous evolutionary era. |
| Mating Dynamic | High satisfaction/alignment with preferred traits. | Severe mismatch between hardwired desire and physical reality, maximizing sexual conflict markers [10]. |
Here is more scientific data which helps you understand how these genetics do not influence human sexual mate selection.
Studies on large-scale genetic registries of twins show a ~0% influence on the human sexual mate selection for a human with specific physical traits (e.g., facial structures, height, weight) [1].
So, "Genetic Parental Imprinting" is a scientifically inaccurate idea which asserts "Your DNA contains a hardwired, highly specific genetic photograph of your opposite-sex parent’s face to use as a romantic template". Humans inherit an algorithmic framework for assessing health, facial symmetry, and phenotypic quality, but they do not inherit static mental images of specific faces.
Here is an analogy.
A factory-reset phone contains an operating system with code. This code determines how the phone interprets data, renders graphics, and processes inputs. However, the factory-reset phone does not contain photos or customized settings.
A human's genetic mate selection preferences are the equivalent to the factory-reset phone and the custom content and settings are implemented through other means.
What is environmentally imprinted behavior for human sexual mate selection?
Environmentally imprinted behavior for human sexual mate selection is defined by a human's social environment.
This social selection ensures a human's sexual mate selection can be adapted to different environments the human did not evolve in.
You can extrapolate this logic to understand how a human's upbringing can influence their sexual mate preferences.
What is Social Parental Imprinting?
Social Parental Imprinting is the idea that "Your brain observes your caretakers during childhood and manually internalizes their physical traits as a safe, baseline template for what a human mate should look like."
So, this preference is not inherited by genetics.
Here is the scientific data.
Studies show a small but statistically significant tendency for women to pick long-term partners who physically look like their biological brothers [12].
Here is the logical deduction for this preference.
- A
mix of a woman's parents' physical and social traitsare imprinted onto the woman's sexual selection preferences.- So, the woman prefers men with a
mix of a woman's parents' physical and social traits.
- So, the woman prefers men with a
- Her brother's physical and social traits are similar to the
mix of the woman's parents' physical and social traitsin the male-form. - So, the woman prefers men who look like her biological brother [12].
Here is an analogy.
Suppose you take pictures with a factory-reset phone and save them to a folder named "what-a-safe-human-looks-like". Then, you open this folder every time you make a decision on whether to date a person.
A human's childhood brain is like both
- the camera you took pictures with
- and
- the file system which stores the pictures you saved.
What is Contextual Mate Shifting?
Contextual Mate Shifting is a theory which asserts "Humans change what they look for in a mate depending on the timeline of the relationship" [13].
- Visual, physical templates dominate short-term choices (sexual behavior) [13].
- Psychological, resource-driven traits dominate long-term choices (provisional behavior) [13].
Here is the scientific data.
Studies show
- In Short-Term Contexts (Sexual Behavior):
- Men and women place a hyper-priority on strict visual templates—like youth and physical fertility cues [13].
- In Long-Term Contexts (Provisional Behavior):
- The brain prioritizes psychological and social traits—like kindness, reliability, and cooperative parenting skills—because these are the resources required to keep offspring alive [13].
Sources Used
[1] Zietsch, B. P., Verweij, K. J., Heath, A. C., & Martin, N. G. (2011). Genetic and environmental influences on human mate choice and mate preferences. Behavior Genetics, 41(4), 512-525.
[2] Wikipedia. Major histocompatibility complex and sexual selection. en.wikipedia.org/wiki/Major_histocompatibility_complex_and_sexual_selection.
[3] Wedekind, C., Seebeck, T., Bettens, F., & Paepke, A. J. (1995). MHC-dependent mate preferences in humans. Proceedings of the Royal Society of London. Series B: Biological Sciences, 260(1359), 245–249.
[4] Chegg Academic. Fisher's runaway sexual selection hypothesis explained. chegg.com.
[5] Connallon, T., & Hall, M. D. (2020). On the logic of Fisherian sexual selection. Evolution, 74(12), 2565-2575.
[6] Pomiankowski, A., & Iwasa, Y. (1998). Runaway ornament diversity caused by Fisherian sexual selection. Proceedings of the National Academy of Sciences, 95(9), 5106–5111.
[7] Carrier, R. (2022). Fisherian Runaway Doesn't Work Like That: Manosphere Pseudoscience Strikes Again! richardcarrier.info.
[8] Snow, S. S., Alonzo, H., Servedio, M. R., & Prum, R. O. (2019). Female resistance to sexual coercion can evolve to preserve the indirect benefits of mate choice. Journal of Evolutionary Biology, 32(6), 545–558.
[9] PMC Evolutionary Biology. Female Resistance to Sexual Coercion Can Evolve to Preserve Indirect Benefits. ncbi.nlm.nih.gov/pmc/articles/PMC7045708/.
[10] Wikipedia. Sexual conflict in humans. en.wikipedia.org/wiki/Sexual_conflict_in_humans.
[11] Buss, D. M., & Schmitt, D. P. (2023). The Sexual Selection of Human Mating Strategies. labs.la.utexas.edu/buss/files/2023/04/The-Sexual-Selection-of-Human-Mating-Strategies-2023.pdf.
[12] Saxton, T. K., Steel, C., Rowley, K., Newman, A. V., & Baguley, T. (2017). Facial resemblance between women's partners and brothers. Evolution and Human Behavior, 38(4), 429–433.
[13] Kenrick, D. T., et al. (1990). Evolution, traits, and the stages of human courtship: Qualifying the parental investment model. Journal of Personality, 58(1), 97-116.