In This Article
Spring Fever?
Do you think human beings are made to mate at a certain time of year?
Throughout nature, we see seasonal breeding as part of species survival. Most animals are forced to mate in the summer-fall, in order to give birth in the spring.
Mating during late fall or winter would push birthing into summer, which would not allow ample time for the babies to develop and become self-sufficient enough to survive and thrive during a cold and long winter.
In the Arctic, many species are forced to mate within a one-week window in order to give offspring time to develop and prepare for winter!
Research by Dr. Russ Reiter suggests the hormone responsible for these mating cycles is melatonin. Melatonin is, of course, the master hormone produced in the pineal gland that regulates our connection to the light-dark seasonal or circadian cycles. During longer nights of winter, we produce more melatonin. The shorter nights of summer trigger less release of melatonin.1
We recommend "Artificial Light Now Linked to Sugar Cravings + Melatonin Imbalance": https://lifespa.com/artificial-light-now-linked-sugar-cravings-melatonin-imbalance/
The Pineal Gland + Melatonin for Seasonal Breeding
The only reliable indicator of the changing seasons is the number of hours between sunrise and sunset. For example, in June, you can have temperatures as high as 85° or as low as 25° in many parts of the US, but the number of hours between sunrise and sunset has been pretty much the same for millions of years.
The precision of these cycles is interpreted by the pineal gland through production of melatonin. Melatonin orchestrates the ebb and flow of our biological clocks, numerous hormones and in particular sex hormones that have ensured the survival of our species.
As the days begin lengthening in the spring-summer, melatonin levels are suppressed and reproductive hormone activity is increased. In winter, when nights are long, melatonin levels surge and reproductive hormone activity is suppressed.2,3 Increased winter melatonin is a natural means of contraception for many species, possibly including humans. In the 1990s, a melatonin birth control pill was under development.3
Since melatonin production is linked to light exposure, using melatonin as a birth control agent might be effective—as it was in traditional cultures, when sleep was initiated by sunset and activity by sunrise. However, it would be a pretty unpopular birth control pill, as the fine print may have to read, “Possibly only effective if sleep and total darkness is initiated just after sunset.”
In the end, The Dietary Supplement Health and Education Act of 1994 classified melatonin as a dietary supplement—thus, the development of melatonin as a birth control pill was squashed.
For millions of years, animals have synced up their breeding schedule with this predictable light-dark cycle. Melatonin is also responsible for changes to the color and thickness of the coats of animals and migration patterns.1
Dr. Reiter’s first studies evaluated hamsters. Hamsters’ testicles literally shrink during winter. In the spring, they swell to a considerably large size in proportion to their body. If hamster-sized testicles were on humans, they would weigh about eight pounds. This interesting characteristic makes the potential of testicular atrophy during winter extremely likely.1
Dr. Reiter and his associates discovered that the molecule involved in the shrinking or shriveling of the testicles each winter was melatonin. Increased of melatonin (linked to longer nights and long, cold winters) translated into an evolutionary trait that decreased sex drive and paused mating activities.1,2
In the 1890s, Eskimos were studied before exposure to the modern world and artificial light. In one of these cultures, during the long winter months with little or no light, women would completely stop menstruating. Their melatonin levels were also surging during these months. Come spring, when it was lighter for longer, melatonin levels would be suppressed, reproductive hormones would surge . . . and mating season would begin!5
In Northern Finland above the Arctic Circle, there is an eight-week period during summer where there is a significant surge in conception rates, and an associated boost in spring births. Researchers discovered that during this surge, there is a significant drop in melatonin levels.4
There is also a drop in melatonin production around the time of ovulation during a normal menstrual cycle. According to Dr. Russ Reiter, it is possible that this dip in melatonin production during ovulation is linked to increased fertility during that time.1,4 There is also a short surge in testosterone during ovulation to ensure an ample reproductive libido.
Our excessive exposure to artificial light after sunset has resulted in a disconnect to natural light-dark cycles. Many adult humans are producing less melatonin year-round than they normally should. This chronic melatonin deficiency is linked to a litany of health concerns and has become a new emerging branch of western medicine called, circadian medicine.
Premenstrual syndrome (PMS) symptoms such as headaches, weight gain, cravings, poor sleep, and irritability have all been linked to a decrease in melatonin production. Studies show that women with PMS produce less melatonin than other women, particularly a week before their cycle starts.1,6
Many experts believe humans were once seasonal breeders like all other mammals. As artificial light was first introduced in the form of fire, humans stayed up longer into the night, slowly altering the natural circadian production of melatonin and other sex hormones.
Soon, the long nights of winter that suppressed conception rates were replaced with more artificial light, resulting in less sex-hormone suppression. It seems that over thousands of years, we traded our seasonal breeding instincts to be able to breed year-round, as we do today.
That said, there are still significantly higher birth rates in the spring in the colder climates compared to any other time of year.4,5
What do you think . . . a coincidence? We would love to hear your thoughts!
We recommend "Live With the Natural Cycles": https://lifespa.com/live-with-the-cycles/
In Northern climates, a Spring birth was optimum for mother and child because the increased sunlight duration gives both a shot of Vitamin D that is essential to good health and good survival rates for the child.
That is also the reason that the traditional wedding month is June..
Dear Dr John, thanks so much for all your great articles! Interestingly, for the first time, I would like to share a very different opinion. In the great history of India, we learn the Ramayana and there is a point when an awesome personality called Lakshmana says that people are more interested in giving a vent to their romantic needs during winter as the nights are longer. I suppose things might vary across geographies due to the typical climatic conditions. Take care!
Hi Sudha,
Thanks for your thoughts! They are insightful, and food for thought.
Be well
Interesting.As one who is also an expert in Ayurveda you will no doubt agree that diet also has a role to play in sex.Certain foods have been classified as having aphrodiscal attributes and hence have been prescribed to be consumed during certain periods.As observed by Sudha R climatic conditions contribute in a big way….Indian subcontinent,China, most parts of Asia,Africa and S.America are where the population is overwhelmingly large.
Thanks , great article, something to think about.
Strange,
I came here from East Asia to North America and I can’t find nearly as many dates and matches on my dating apps in winter as in summer.
No matter how much time I spend on those apps I don’t see matches esp. with white people. I think white people (the cute types) are not into asians like me, but then in summer I do get matched with many of them all of sudden. I’m mostly homosexual.
This is very strange I found but I realize there is actually some science behind it..
Its canada btw and yes the winter day is 9 hours long while summer is 15 hours long. On top of it winter is frigid and gloomy and summer is cool, sunny and paradise-like. A typical example of sun light hour binary.
Wen light is a indicator it cut by of influence in the modern world.
As Hitler said, the bigger the lie the easier it is to believe! repeat it long enough, loud enough and you will believe it yourself! Worth to mention that the 2 week strict fasting in remembrance of The mother of God ascending to heaven, is coming. And during this period, no mating occurs among believers. Of course if a party in the couple has desire, then the other party is blaspheming to deny! breaking the holiness of the fast is better than essentially pushing your mate onto adultery! A husband’s body is controlled by the wife and the wife’s body is controlled by the husband!
I searched this because I seem to be Way more sexually active and in tune come end of September and October like idk what got into me and wondered why. my son was born in July. every year come October and I’m like “I want a baby ” it’s so weird to me why not any other time of the year
Thank you for the article. Good information on the role of melatonin and conception and desire for reproduction. Pitta season is in the summer where transformation is high- egg + sperm transforms into human. Perfect for conception. Kapha season is spring which forms building blocks for baby’s structure. We see so many things spring into life in spring. 😊. Would more births happen in say October in New Zealand then?
Love your work!!!
Hi Elizabeth,
Seasonally, yes, you would expect to see the same pattern but in different months, due to the different seasonal changes.
Best,
LifeSpa Staff
Where I grew up – SF Bay Area – we had something called mid-term, where the school class was divided into two groups so children would be with their own age group. There was Dec-Apr group (mine) which is 5 mos, and May-Nov, or 7 mos. At HS graduation our January, smaller class had 250 grads, while the June class had 750. With only a 2 month disparity, what caused the huge differential?? We determined that the larger class was CONCEIVED during the longer, colder winter months. Those longer-night months included Holidays like Thanksgiving, Xmas, New Years … and Valentine’s Day! while my classes conception time was in the warmer months, including summer where the mom might have to tend to siblings not attending school. Bottom Line: Homo Sapiens are out of tune with the normal laws of Nature!
Hi Ron,
Yes that is a good example of humans being out of sync with our natural circadian rhythms.
Best,
LifeSpa Staff
Hooray, hooray, the first of May,
when everyone comes out to play!
Humans are from God! We are not animali! We mbv ate whenever we feel like it, light or no light, period!!!
Loved this thank you and happy spring!
Love and light from Australia
India has some 70,000 births a day, give or take. I don’t think anything matters here. Sun or rain or famine or drought or virus or poverty or drug addiction….. or anything…..
Love the article! This is a fascinating idea to chew on. I definitely find that as the day is longer and warmer, I feel drawn to be more social and seeing new birth come about in all the animals kindles the idea of how lovely it would be to have my own children. It would be interesting to see if there is any correlation between what season you were born in and what is your Prakriti. Also I was born in early spring as are many of my siblings (I am 1 of 8 children and 5 of us were born early February-may) so there is definitely a natural tendency for my parents to procreate in the late spring/summer. I recall reading about ojas though and how in the winter we can have more regular sexual activity as ojas is higher and in the warmer months with so much outdoor work and physical activity we can easily become depleted if there is too much dispersion of reproductive fluid? Hm just some thoughts..