Monogamy, the idea of being committed to one partner at a time — is seen as the normal way to be in romantic relationships in many cultures. But if we take a step back from culture and look at biology, behavior, and animal life the query becomes more interesting: Is monogamy natural?

In this blog, I will discuss how monogamy looks like from human and animal perspectives, explain what the science says about it, and how evolution, culture, and biology figuratively put the pieces of our intimate puzzle together regarding human relationships.

What is Monogamy?

Monogamy is fundamentally a mating system in which an individual has only one partner during a given time period – sometimes for life, but sometimes only for a breeding season. Monogamy can be emotional, sexual, social, or some combination of those. In humans, ‘monogamy’ typically means a long-term romantic and sexually committed relationship with one partner, however, it varies depending on culture and individual values.

Is Monogamy Common in the Animal Kingdom?

The natural world tends not to follow the rules of lifelong monogamy – it is the exception, not the norm.

• Birds are the most monogamous group in the animal kingdom. Approximately 90% of the 10,000 bird species are monogamous, mainly for the purpose of co-parenting.
• Mammals are typically not monogamous. Fewer than 10% of mammal species are socially monogamous, including beavers, wolves and gibbons.
• True monogamy (sexual exclusivity with pair bonding) is extremely rare. In species that are considered “monogamous”. Genetic information often indicates that individuals have offspring not sired by their social partner.

Is Monogamy Natural to Humans?

The answer is complicated.

1. Biological Evidence

Humans are not biologically monogamous. Our closest biological cousins, the chimpanzee and the bonobo, are extremely promiscuous. Both pair bonding and mating with multiple others were part of our evolutionary history, allowing for flexible monogamy

Some biological evidence suggests this duality:

• Testicle size: Humans are somewhere in between chimpanzees (large testicles indicating sperm competition) and gorillas (small testicles for harem mating). This suggests mixed mating behavior.
• Long-term parental investment: Human babies have a very long dependence period, therefore it is advantageous for the survival of babies to pair bond with caregivers who might be monogamous.

2. Cultural Evidence

Cultural and religious practices have play an enormous role in denoting monogamy as the societal norm, especially in Western societies. More specifically throughout history:

• Polygynous (one male with several females) arrangements were commonplace in ancient times and cultures.
• Some tribal cultures had polyandrous (one female with several males) arrangements.

Serial monogamy – with one partner at a time but multiple partners over a lifetime – is increasingly popular these days.

In most ways, cultural evolution has created monogamy as much as (or more than) biology itself has.

What Psychology Says About Monogamy?

Humans fundamentally want intimacy, connection, and emotional security. Monogamy provides the opportunity to meet these needs often through trust, companionship, or long-term partnership. Nonetheless, monogamy comes with its challenges, which include:

• Sustaining passion during decades of partnership
• Dealing with desire, temptation, and infidelity
• Aligning desires with personal growth over time

We have some people who are highly successful monogamists, and others who feel fulfilled (and authentic) through either ethical non-monogamy, or polyamory. The ultimate question is not what is “natural,” but rather, what is authentic to them.

Why is Monogamy often Debated as the “Correct” or “Better” Way?

Monogamy is constantly idealized — but why?

• Social Stability – Monogamous relationships often provide a basis of social stability. Norms that specify two members limit competitors for mates but also provide a level of social cohesion, especially in large towns and cities.
• Parental Investment – When children are born in monogamous relationships, both biologically and socially parents are more apt to invest their funds, resources, and time into the child’s rearing, which increases the survival of offspring and rearing a healthy family, or at least a better chance at healthy family rearing.
• Emotional Security – Monogamous relationships often have predictability, trust, and strong aspects or sense of partnership, which can ultimately provide reduce anxiety (and for some any) promote more positive self-esteem, and promote long-term emotional health.
• Cultural and Religious Expectations – Monogamy is idealized by many religions by referring to marriage as a moral ideal that is synonymous with loyalty, discipline, and family.
• Legal Norms – In many areas, legal norms exist that legally necessitate monogamous marriages — there are legal protections, tax benefits, and social structures that polyamorous or non-monogamous relationships will never receive.

That being said, just because something is “seen” as right, doesn’t mean it’s is going to be right for everyone. The key is the compatibility of each partner or the persons involved in the relationship and decision-making.

Why Does Monogamy Work for Some and Not for Others?

One of the reasons monogamy works for so many people is due to several components, including:

• Social support and division of labor (or responsibilities)
• Emotional bonding – aided often by oxytocin and other neurochemicals
• Personal values or religious beliefs

For others, monogamous relationships often feel confining, constraining, and misaligned with their wants and desires. As stigma decreases about relationship styles, many people are experimenting with alternatives that include:

• Open-relationships
• Polyamory
• Relationship Anarchy

These alternative options are not “unnatural” relationships, and are simply components of the continuum of relationships that exist between human beings.

Monogamy in a Modern World

With apps for dating, ability to travel around the world, and changing gender roles, monogamy is shifting. Younger generations see traditional definitions of monogamy changing, and are more willing than any generation before to develop relationships that suit their needs and desires – not society’s.

The idea of finding somebody to be with “forever” is still romantic, and still possible – but it may no longer be the only option for finding connection and love.

Conclusion

So, is monogamy natural? Biologically, it’s not our default option – though it’s not necessarily unnatural, either. What makes us unique is that humans can build deep pair bonds, and also have a variety of mating strategies.

Asking if monogamy is natural is less important than asking whether it feels right for you. Whether you choose a lifelong partner with one person, or it feels good and natural to find love in different ways, the most natural thing to do is choose dictation with honesty, intention, and respect for everyone involved.

Read about: What is Monogamy? Exploring Love, Loyalty & Alternatives