My Medieval kingdom has birth control, why is the population so high?

Question

My world is roughly the same as the middle ages but has a natural form of birth control in the form of a root that can be grown and consumed to prevent pregnancy.

Because of this root, opportunities to receive education have opened up to those women who can afford it.

However, birth control and access to education for women have historically been associated with a sudden and dramatic drop in birth rates.

For lore reasons the population needs to be relatively high similar to what it was during the middle ages.

Is there a reasonable explanation for why the population wouldn't drop despite having access to birth control?

The birth control root, while not cheap, is not expensive either. Definitely affordable to the noble and merchant classes, and to lower classes to a limited degree.

Answer 1

There are a lot of comments now and I won't read them all so sorry if I repeat a few things that were said but here are my two cents.

1. There were forms of birth control in the middle ages and long before which probably would have worked to a similar extant you describe yours. Therefore, I don't think you even need to acknowledge this.
2. The number of kids who die is a big factor as opposed to birth control alone; people are willing to have less kids if they know they will all (likely) survive. Therefore people in your world might be more likely to have less kids if there is other medicine and child mortality goes down.
3. If you still feel strongly that this needs to be explained, which I don't think it needs to be, you can perhaps think about what causes high birth rates in Israel which has by far the highest birth rate amongst OECD countries. Some factors that contribute to this are likely religion (which says you should be fruitful and multiply), baby boom to replace people who were killed in WWII, and flexible work life and a lot of help with kids from family encouraging women to have kids and continue living their lives.

https://www.taubcenter.org.il/en/research/why-are-there-so-many-children-in-israel/#:~:text=People%20often%20mention%20two%20factors,children%2C%20reduced%20working%20hours%20following

https://www.thejc.com/lets-talk/all/the-riddle-of-modern-israel's-remarkably-high-birth-rates-2d3Ch8U5grh4kAYH42j7sR

Answer 2

A Lack of Birth Control Wasn't the Cause of Large Families

As one commenter already pointed out, the reason people had large families in the Middle Ages wasn't because they couldn't avoid it; rather, it was a combination of factors:

• The desire that enough of one's children would survive to adulthood despite the enormous infant and childhood mortality rates.
• Particularly in rural settings, the desire to have people to work and inherit the land.
• A nearly complete lack of rights for women. The availability of birth control doesn't matter if the lord of the manor wants to sire a dozen heirs.

You've already indicated that the root would be an expense for peasants, and the population growth in the Middle Ages was not led by the nobility or merchant classes.

Also:

Because of this root, opportunities to receive education have opened up to those women who can afford it.

Unless your culture is very different than the European middle ages, again, childbirth/motherhood was not the principal obstacle to women being educated.

Answer 3

You've missed the other great factor in plunging birth rates, and that is the death rates. If birth rates were the only factor, why did overall population growth remain flat or very low throughout thousands of years before industrialization happened, even with birth rates far above what we see in first-world nations today?

Life Expectancy:

Historically, life expectancy figures have been far lower than in modern times. However, this is because the statistics commonly expressed in this comparison are for average life expectancy; there's a separate measure for maximum life expectancy (which is what many people think of in practice), which is essentially defined as the average across the top 10% of longest-living people, so it's only really considering people who survived to be old. People die long before reaching old age for any number of reasons, which drops the average significantly if they're common enough: accidents, warfare, disease, the list goes on.

The trick here is that the gap between average and maximum life expectancy is much smaller in modern times than in pre-industrial times. Historically, people who lived to adulthood had very good odds of surviving to reach 60 or 70 (even warfare usually took only a small percentage of the male populace away, as most had to keep working the fields), despite average life expectancy usually being 40 years or less. This is almost entirely due to infant mortality rates. Before the industrial age, half or more of babies didn't survive their first five years. Those high birth rates throughout most of history don't mean that the babies all grew to be adults and started their own families. A family would often have five or six children just to see two survive to maturity. Royalty and wealthy families (who tend to get more of the detailed attention in historical records, naturally) might have been prone to having more survivors, but they had access to the best food and medical care, so of course they'd beat the average.

Replacement Rate:

In nature, birth rates and death rates over the long term typically balance out to keep a population stable: temporary distortions are inevitable, but persistent deviations towards extra births mean an expanding population, which requires more territory, more food, and more resources in general. The "replacement rate" (the rate of births needed to maintain that equilibrium in a given environment) is generally close to the actual birth rate: the post-industrialization population boom happened when death rates plunged very quickly and our instincts and society didn't catch up. In modern first-world nations, this is about 2.1 births per female (a rate lower than 2 is impossible for humans, assuming equal numbers of both sexes), since infant mortality is very low, random car crashes and the like kill only a tiny proportion of all children, etc., so nearly everybody will have their chance to have children. In older times, when a much smaller share of children survived to reproduce, that necessary replacement rate rose accordingly.

For my part, I don't think that education of women was the main factor in cutting down birth rates: not that that isn't a relevant factor, but I would put it third in line at best. The rise of sanitation and food security are the two big ones. With sanitary improvements (and medicine in general, but proper sanitation and cleanliness were key), infection and disease plunged, which means a lot less infant mortality. Food security is also crucial, because in medieval societies one year of drought often caused severe famine, thousands of dead from starvation, possible societal collapse, etc. With improving supply networks, large-scale food preservation, and so on, shortfalls from one area could be covered by a surplus elsewhere, ensuring a reliable yearly minimum of food high enough to actually feed everybody. Education might have dropped the birth rates, but sanitation and food security are what allowed society to survive those drops.

Conclusion:

Frankly, I don't see your birth control being used all that much in a medieval society. Some would, certainly, but regular users would form a small proportion of the overall populace, because you'd still be losing a lot of children to the various causes of infant mortality, and so you'd need to have more children to replace those that died. There's absolutely individual cases where birth control would be desirable, but in the big picture they would be a minority.

Also, you've noted that your birth control is expensive enough that the lower classes have "limited" access to it, which means it's too expensive to be used continuously by the largest segment of the population. Peasants and farmers would be putting spare funds into simple survival, because medieval societies didn't reliably have a surplus; they can't afford to waste money on what is effectively a frivolity when they're trying to make sure their children are fed.

Answer 4

In a medieval setting, you would want to have the highest possible population because it was profitable. For peasants (i.e. the vast majority of the population) children were probably the best investment available to them, and could start contributing to the household's economy at (what seems to us) a surprisingly young age. For nobles, bigger population meant more labourers to work their lands, providing more surplus production to be extracted as the noble's income. They might well have had access to a contraceptive, but not enough reason to routinely use it. We can be sure about this because contraceptives did exist in medieval times, and did not cause a population drop.

Answer 5

Jdunlop has given a pretty good, well reasoned (but boring) answer - but there are some others that are more fun/interesting.

People like to f....ornicate

The first is very simple: People like to have Sex. A Lot of Sex. Even with modern contraceptives - it's a 1 in N chance of getting Pregnant (Condoms are 1 in 50 IIRC) - so have your society where people like to have a lot of Sex.

It could be due to cultural reasons (Mass Orgy on Sunday! Bring your friends!), it could be Biological (The males are all well-endowed and the Women regularly climax), it could be less-positive (Lots of Rape/sexual assault).

Religion!

No one mentioned the Pope in the room? I told you to go forth be fruitful and multiply!

Even today the Catholic church is opposed to Contraception, I believe there are similar prohibitions in the other Abrahamic faiths. Even if we put aside a prohibition against using the contraceptive for part or a significant part of the society - we can still go with the above - their religion encourages regular sex!

Natural differences in root strength

This is one of the big issues with 'natural medicine' - consider Cannabis - two different plants can have wildly different THC content (the active chemical) - meaning that for a given weight consumed/smoked you could be getting either a double or triple of the required dosage or not enough. Whereas Modern Medicine has the ingredients refined down to a precise amount.

This natural variation can mean that it's not as effective as it otherwise would be. Then throw in natural variations of fertility, perhaps even throw in some other common foods that interfere with it (IIRC Grapefruit and the Pill don't get along well - Maybe some ladies can confirm) and you've got something that means it's not effective enough at causing a declining population.

Bloody Melee and Hand-to-hand combat

What does this have to do with Children? Well, why are the Baby Boomers called that? You had a lot of young men, who had gone off to War (WW2), seen their own mortality and had an innate evolutionary desire to extend their genetics - by spreading their seed far and wide. The result? a Big increase in population. This is as true today as it was then.

Add in that Wars/Fighting means that there is less Men available (as they die in combat) so the average Man has higher sexual value than usual - - therefore they get to be horndogs and sleep with more women than perhaps they otherwise would.

On the flipside - Women love a Man in uniform and love a victorious hero - all that Testosterone flowing around from surviving melee combat and all that estrogen flowing from seeing a Man risk his life for the sake of the city = lots of post-combat sex and that means a lot of babies.

Answer 6

They don't get educated

The vast majority of medieval population was not educated. It was commonplace for nobles and even royalty to be illiterate; they had clerks to write and read for them.

Medieval culture lived very close to the margins. No one was going to spend the time and money to educate people who could not make immediate practical use of it. Why would you teach a girl to read when you could put her in the fields shouting to scare birds from new-planted seeds? Or carding wool? Or spinning?

Not to mention the fearfully high child mortality rate meant that many babies were needed to attain replacement birth rates.

Answer 7

Middle ages population was not determined by birth rates

The middle ages where a period when the Malthusian trap was in full swing. During the Middle ages, the primary source of wealth was food - having it, being able to produce it, etc - with much of the population devoted to it.

A small percentage of the population didn't produce food - the crafters, merchants, townsfolk, and nobility mostly.

Whenever the wealth of society increased, the population soon followed. It grew to the point of malnutrition, where there wasn't enough wealth for everyone to be food secure and healthy, and then fell with famine or disease or war.

After a famine or disease caused the population to fall, wealth per person would increase, followed by a population increase and a collapse in living standards.

While most of the population is working on producing food, the food capacity of the area is determined by the workable land moreso than the number of people working on it. Adding more hands increases yield, but only marginally - so you get more total food out of a parcel of land, but less food per person, as you add workers.

When the population is low, there is lots of surplus food. As population grows, the countryside exports people to the cities (2nd sons who aren't inheriting the land and don't want to be 2nd class peasants in the country). The cities are a population sink, with more people starving/dieing than being born there, but still better off than being a vagrant in the country: you have a chance of being successful.

In areas that split land instead of handing it to the eldest, instead you have the farm plots getting exponentially smaller, until they are no longer big enough to produce food for yourself let alone your lords tax demands. A rich farmer who had lots of land and could employ dozens of labourers would in 6 generations produce a bunch of poor heirs who couldn't feed their family, even if they only had 4 kids per generation.

It is the food production silly

So to maintain middle ages population, you need to maintain middle ages food production; if you want a middle ages feel, you have to prevent escaping the Malthusian trap.

Birth control alone doesn't do it, because for individuals having more children is going to both be a status symbol and help with the work. You might not be able to support those children's children on your land, but for this generation the help is welcome! The non-eldest surviving kids have to find an alternative to being a land owner (or have peasant rights to farm some land) just as in the middle ages. And if you have enough land to support even a few helpers (which you need if you want to survive a famine), isn't it better to employ your kids than some other family?

Maintain food production levels, and don't give people profitable alternatives to making food, to keep Middle ages style demographics around.

How the real world got out

We found non-human and non-animal sources of energy. When the only work you can do is from food, food determines how much work your economy can do.

Wind, water and coal power provides sources of work that don't require growing food; so the wealth - the useful work done - of an area rises above the crops and animals it can grow.

Unlike food energy, wind water and coal energy cannot be converted into food calories. So production boosts in them cannot be swallowed up with more mouths to feed, not without trading the produced products of that energy away for food. But it does replace difficult work that was done INSTEAD of making food - powered looms replacing human effort at weaving ends up saving a lot of "food calories" and produces something people sacrifice food calories for (cloth).

Having more and more of the economy not devoted to food production, and sustainably so, results in the practice effect - we get better (at a society) as those tasks. Metallurgy, clothmaking, machinery, construction, engineering, entertainment, education -- all skills that we become better at as more of society is aimed at producing non-food goods.

The countryside is still full of people producing food, but as noted if you drop the countryside population in half you get nearly as much food produced. What more, if you drop the countryside population in half, the countryside exports more food because it eats less. And non-human food production -- like using land to grow sheep for wool -- leverages this even further.

The logic of this results in horrible crimes and "clearances" as peasants are forced off the land. The city population swells, but with the industries built on the back of non-food energy there are jobs for many of the impoverished peasants. Coal mining, working on mechanical looms, lumber to provide raw materials for ship building, servants of the increasingly wealthy merchant classes, etc.

Insanely more people working in these non-food-calorie jobs, many of which require education, results in an accumulation of expertise and those jobs becoming more efficient. Write's Law kicks in, making the industries more efficient, which makes doing the industry more profitable, which makes having more people working in the industry economical, which feeds back into itself.

As it happens, this increase in mechanical skills feeds back into food production, dropping the number of workers you need to produce food as tools to increase food production efficiency drop in price and increase in quality.

How to trap your fantasy

You could probably just cut coal. Without coal (or its equivalent) you are stuck with windmills and watermills as your source of non-food calories.

Coals provided heat without using up land to grow wood initially. Coal mining to power steam engines led to better steam engines, both to pump water out of coal mines and to power trains and steamships to move goods around. Improved steam engine design led to more efficient, well, everything - and feedback between metallurgy, mining and energy production spiraled upwards.

Remove coal and wealth remains tied to how many calories of work you can get out of the land, which is fixed.

Answer 8

I'm not sure that this question can be answered in a socially acceptable manner. There are few topics that will get people shouting their one true answer at you as loudly as with birth control.

The factor that is most likely to affect birth rates is whether or not women are allowed to choose whether or not they will get pregnant. Birth control has little or no effect on birth rates in cultures where it is severely stigmatizing or illegal. If women aren't allowed education or full employment, they also lose this choice. In the Middle Ages, it was common for women to continue bearing children, even when the activity became life-threatening.

However, the original question doesn't actually ask about pregnancy rates, birth rates, or even population growth. It asks about population size. Population growth is the difference between births and deaths, and decreased infant mortality can more than make up for a lower birth rate. Population size just means that people aren't dying as fast as they are born. This probably wouldn't be the case if the nobles are still throwing all of their excess men at each other in perpetual warfare, but that isn't a necessary quality for that time period.

Answer 9

How long of a time period is your story set in?

This birth control method might be a relatively recent discovery. Your civilization might demographically collapse in the next several decades, just as some of our current civilizations will if they stay on their current courses. But this does not have immediate effects right now besides some people worrying about the distant future of their culture. So the population is high because it increased rapidly in the past, even if it is declining right now (or will soon begin to decline).

Answer 10

I believe there is something wrong in the assumption that access to birth control would lead to a decrease in population size.

I would expect most persons in a medieval type of society considers having many childrens as something positive from several reasons:

• Quality of life at old age. As there are no pension systems or similar, the children are expected to contribute to their parents old age. Having many childrens is the equivalent of todays saving account.
• Religion: see as example how the catholic church as of today (in our world) thinks about birth control.
• Most of the peasant population probably has not even heard of the birth control root - communication of news is very restricted in a largely non-literate society. This probably means that birth control is only used by a very small part, mostly wealthier, part of the population.
• A larger work force is needed in agriculture work as newer labor saving inventions are not in place, or at least spread very slowly.
• There could be other sociological factors as well. Maybe having children is not only done by land-owning married couples, it could be done in more "loose" relations as well. Perhaps all children are taken care of by a larger group than the main family, and hence any women of child bearing age tries to add children of their own.

Answer 11

Farm families need children in order to thrive.

Families on farms have historically been larger than families in cities. From the age of seven onwards, children in a farm family do some of the work. Enough work so that they are a net plus to the wealth of the family. This is very different from the pattern in an urbanized setting, where children represent a net expense to the family until they are about twenty.

So farm families are not motivated to remain small, even if they can get birth control. This is in addition to the other factors listed in other answers, such as high infant mortality rates.

Answer 12

Seems to me like you have a solution in need of a problem. Think about how your society will work. When all those women are forgoing bearing and raising children in their prime child-bearing years in favor of obtaining an education, where do the children come from?

Answer 13

War in neighbouring countries

Although the other answers are reasonable, you could also consider this reason if it's better-suited to your setting. Historically people flee war, and something similar could apply here. If there's a war in neighbouring countries, their people could flee to your kingdom, and of course your population goes up.

Examples, some historical, some modern:

Siege of Jerusalem in 1187:

Balian found the situation in Jerusalem dire. The city was filled with refugees fleeing Saladin's conquests, with more arriving daily ...

Mongol invasion of Hungary:

Following their decisive victory, the Mongols now systematically occupied the Great Hungarian Plains, the slopes of the northern Carpathian Mountains, and Transylvania. Where they found local resistance, they killed the population. Where the locale offered no resistance, they forced the men into servitude in the Mongol army. Still, tens of thousands avoided Mongol domination by taking refuge behind the walls of the few existing fortresses or by hiding in the forests or large marshes along the rivers ...

During the German conquest of France, phase two:

Between six and ten million civilian refugees had fled the fighting and clogged the roads, in what became known as L'Éxode (The Exodus) and few arrangements had been made for their reception. The population of Chartres declined from 23,000 to 800 and Lille from 200,000 to 20,000, while cities in the south such as Pau and Bordeaux rapidly grew in size.

The roads from Kviv to Lviv were heavily congested during the early phases of the Russian invasion of Ukraine, 2022:

"I'll just get in my car and head to Lviv" was a comment we heard often in Kyiv.

Hundreds of thousands of people had the same thought, judging by the congested roads out of the Ukrainian capital.

Answer 14

Frame Challenge: Why would medieval women bother?

I don't know why you're asking your question, but it might be that you believe that people 1,000 years ago would respond in the very same way as people would or do today to similar opportunities. Said another way, you might not be forgiving the past for being the past.

I say 1,000 years as a bit of an average. The medieval period was from more-or-less 476 A.D. to 1450 A.D. with substantially different behaviors depending on which city in the world you pick to represent your society and which year.

However, oversimplifying to the point that angels weep, we can basically say that it was a mysoginistic world lacking education or even the ability to benefit from education. Men were celebrated for soldiering or mastering a trade. Women were celebrated for having families and a well-managed household. Societies were frequently strongly influenced by religion — and human history easily proves that the easiest way for a church to grow is through births among its members, sugggesting religious pressure would make using the root taboo. Of course, we're completely ignoring the aristocracy as your question appears to be focusing on the majority of people.

But that brings me to my point, why would a medieval woman bother with contraception (generally, not dealing with issues specifically like rape)? What's the benefit? Educated women — especially outside the nobility — were not prized for their education but were more frequently oppressed. Off-hand, I can't think of a significant benefit to using the contraception without changing the society to such an extent that it's no longer representative of the medieval era.

I hope that I'm not putting the proverbial word in your mouth, but you actually can't assume that a demographic of a society in the significant past would obviously benefit as that same demographic does today if they just had access to the "freedom" enjoyed today. In every case, that freedom is enjoyed after all the intervening centuries of change (often bloody change). Corrollary: you can't have the perceived benefit without bringing all that change to the past and it's unreasonable to judge the past by today's standards.

Answer 15

Birth control was already a thing way before the middle ages. The ancient egyptians had it. From Wikipedia:

The Ebers Papyrus from 1550 BC and the Kahun Papyrus from 1850 BC have within them some of the earliest documented descriptions of birth control.

They still made a lot of babies anyway, most likely for the most cited reason in other answers so far: big families were economically advantageous for everybody.

But let's say that in your world death rates are not so high that you need a lot of replenishment, people are educated, and for some fantasypunk reason there is no economic advantage to having many kids. You still have a couple big points of failure in your contraception process.

First, it's a root. It only takes a blight to have everybody lose their contraception. One invasive species of grasshopper or fungus and you will have a long lasting, possibly century-long baby boom.

Second, you need to be a botanist to have safe sex, in a world where illiteracy is the norm (and herbal knowledge possibly makes you known as a witch/warlock). Mistakes will be made, and considering the root isn't cheap (even if not expensive) there may also be a lot of ineffective, fraudulent material in the market.

If your people are really smart they can pursue other contraceptive methods. But like TheDemonLord said, even modern contraception isn't 100% safe if you stick to cheap, non-drastic methods like condoms. Medieval methods would be even less efficient.