Are humans naturally polygamous?

Hormones, Sexual Behavior, Male-Female and Transgender Psychology

During the first year at university, we had four supplementary subjects taught by four part-time external teachers – English, Mathematics, Sociology, and Photography. The sociology teacher was a development worker, who was also a man of progressive thinking. He often said that humans are innately or species-wise polygamous. But we, who came suddenly to university from conservative families and societies, could not easily accept this idea at that time. Before that, studying in a boys’ school and then in college, even talking to girls was a big obstacle for us. There was no scope for chatting or thinking about polygamous or monogamous ideas. However, science and evolutionary experience suggest that humans are in most cases polygamous – whether male or female. Society, civilization, law, and religion often prevent people from expressing this tendency openly. Yet it remains as an inherent human inclination.

Anthropologists and evolutionary psychologists say that humans actually display mixed tendencies – biologically polygamy is possible, but socially and culturally monogamy is more prevalent.

• A Cambridge University study found that about 66% of human offspring are born from the same two parents, placing humans among the top 10 mammal species in monogamous tendency.
• Humans rank between meerkats (60%) and beavers (73%) in monogamy, which is much higher compared to chimpanzees and gorillas (1–6%).
• This proves that humans have evolved towards pair bonding or couple relationships, which is different from our closest primate relatives.
• In history, many societies practiced polygyny (one man with multiple wives), while many others maintained strict monogamy due to religion, law, and social norms.
• In modern society, monogamy is more common for stability, inheritance, and child-rearing, though serial monogamy (multiple partners over time) is very common.
• In some cultures polygamy is still legally permitted, while in others it is considered a crime.
• Humans actually balance between quantity versus quality strategies:
• Men generally lean towards numbers (more partners → more reproductive success).
• Women lean towards quality (supportive partner → higher survival chances for offspring).
• This balance makes humans neither fully monogamous nor fully polygamous, but rather adaptive strategists depending on situation and culture.

🧬 Male Hormones and Sexual Tendencies

The main hormone in the male body is testosterone, which increases sexual desire, aggression, and impulsivity. Research has shown that the higher the level of testosterone, the greater the number of sexual partners a man may have. In society we often see – many seemingly happy family men or acquaintances in office and friend circles keep multiple female partners. Outwardly they may act like saints, but in reality they cannot escape this innate tendency.

• Male reproductive success is largely based on quantity over quality.
• Women bear the burden of pregnancy and child-rearing, so their reproductive success is quality over quantity.
• Therefore women are more selective in choosing partners, while men tend to show comparatively polygamous tendencies.

A man may, during a brief encounter, go to bed with a woman if given the chance, without thinking whether he will ever meet her again or what her emotional state will be. Male reproductive success is generally considered quantity over quality, meaning the more partners men reproduce with, the greater the chance of spreading their genetic legacy. From an evolutionary perspective, men do not bear the physical burden of childbirth, so they tend to show polygamous tendencies and may be interested in short-term relationships. On the other hand, women face pregnancy, risks during gestation, and the responsibility of child-rearing, so they are more cautious and selective in choosing partners. For this reason, men’s reproductive strategy depends on numbers, while women’s depends on quality and stability.

A woman does not become interested in physical relations with a man during a brief acquaintance; she first wants to build emotional bonding and verify how much the man can protect and support her. Evolutionary experience has taught her that after pregnancy she will need long-term support from another, as she may lose her working capacity and worry about the future of her unborn child. Therefore strong, hardworking, responsible, powerful, and self-reliant men are always on a woman’s priority list. But just these qualities are not enough to gain a woman’s trust; emotional attachment is needed so that she can be sure the man will stand by her. Physical relations without this emotional attachment feel to a woman much like a coercive experience. That is why women give more importance to quality than to the number of physical relationships.

💖 Estrogen, Oxytocin and Male Emotions

Men have about twenty times less estrogen compared to women. This small amount of estrogen helps men to feel romantic emotional love.

• Estrogen increases oxytocin sensitivity.
• Oxytocin is called the “love hormone”, which creates bonding and emotional attachment.
• When men use aromatase blockers, estrogen decreases and testosterone remains normal. As a result, emotional bonding during sexual relations is almost absent.

Imagine, a man suddenly falls in love with a gypsy girl named Josna on the road – at first sight the love is mainly an excuse to sleep with her. Or with a sex worker, he keeps talking about love stories while sleeping with her. But after the sexual act is over, will that urge of love remain? Or will he quickly leave her and be free?

Men have about twenty times less estrogen compared to women, but this small amount of estrogen increases oxytocin receptor sensitivity in the male brain. As a result, they can experience romantic emotions, bonding, and love beyond sexual relations. Oxytocin, known as the “love hormone”, is a neuropeptide produced in the hypothalamus and released from the posterior pituitary gland. In men, it helps build social relationships, increases bonding during sexual relations, and strengthens paternal bonding such as when holding a newborn. Thus, even without carrying a child in the womb, a father’s love for his children is created in this way.

🔄 Post-Nut Clarity and Short-Term Mating

A well-known phenomenon among men is post-nut clarity – the sudden decrease of interest in the female partner after ejaculation.

• This tendency becomes stronger when taking aromatase blockers.
• With higher testosterone, men become more short-term mating oriented.
• That is why after a breakup many men go to the gym, because exercise increases testosterone and creates attraction towards new partners.

The relationship between estrogen and oxytocin plays an important role in men’s emotional experiences. Estrogen increases the effectiveness of oxytocin receptors in the brain, thereby enhancing bonding, trust, and emotional intimacy. But when estrogen decreases, such as with the use of aromatase blockers, oxytocin sensitivity weakens and men feel less emotional connection during sexual relations. This is linked to “post-nut clarity” – after ejaculation, testosterone-driven impulsivity decreases and oxytocin-driven bonding weakens. When estrogen is low, this tendency becomes even stronger, which aligns with short-term mating strategies according to evolutionary psychology.

🌈 Transgender Individuals’ Hormones and Psychology

The experiences of transgender individuals are different. When they take hormones of the opposite sex, both mental and physical changes occur.

• Trans women (male to female) taking estrogen experience increased oxytocin sensitivity, resulting in stronger emotional connection and bonding.
• Trans men (female to male) taking testosterone may experience increased sexual impulsivity and aggression, which reflects behaviors similar to cisgender men.
• Hormone therapy brings not only physical changes but also alters mental experiences.

The experiences of transgender individuals are essentially a unique journey shaped by hormones. When they take opposite-sex hormones, not only the body but also mental experiences change. For example, trans women taking estrogen become more sensitive to oxytocin, leading to stronger emotional connection and deeper bonding. On the other hand, trans men taking testosterone experience increased sexual impulsivity and aggression, resembling cisgender male behavior. In fact, hormone therapy is not just about external changes but also reconstructs inner feelings and social behavior. Everything depends on how much of which hormone is taken – it is entirely a subtle play of hormones in the body.

🧠 Psychological Effects

• Hormone therapy creates psychological alignment with gender identity for transgender individuals.
• They feel harmony between their body and mind.
• However, these changes are not always easy – often social pressure, mental conflict, and relationship complexities arise.

Male and female hormones deeply influence sexual behavior and partner selection. Testosterone makes men impulsive and polygamous, while estrogen and oxytocin create emotional bonding. Hormone-regulating drugs like aromatase blockers reduce emotional bonding in men. On the other hand, hormone therapy plays an important role for transgender individuals in shaping their identity and psychological balance.

Humans can be described as socially monogamous but biologically flexible. Our evolutionary history has leaned towards pair bonding, yet cultural and individual behaviors also show expressions of polygamy. In other words, humans are not inherently “polygamous” – rather our nature is a blend of monogamy and polygamy, shaped by biology, culture, and environment.