[nectar_dropcap]D[/nectar_dropcap]o you remember when school was out and there was a kind of a buzz? But back then you didn’t really know what it was. The weather was hot and the girls were dressing less but only to check out the guys to tell them who’s best.

It’s easy to assume this was a human mating season in practice, but I’m afraid to say it’s just what they call a summer madness.

These words were adapted from Will Smith’s ‘Summertime’. It’s true that the summer can feel like a natural aphrodisiac. However, biologically speaking, can we define it as an actual mating season?

When we think of mating seasons, we think of herds of animals simultaneously becoming sexually responsive to each other for a brief period of time. Animalistic orgies erupting from primal urges, deep-rooted within their desire to reproduce; males become protective, females receptive.

For a salmon, it may follow a hundred mile swim upstream battling strong currents and rapids to allow for reproduction. Or conversely, a female panda’s pathetic 2-3 day window of being “in heat” which occurs once a year.

These seasonal breeders have windows of conception to coincide with ambient temperature, food and water availability, and reduction in predation at the time of birth[1]. Females create these windows to increase the survival of their offspring.

But technically speaking, we don’t have ‘windows’ like this. We’re not seasonal breeders. We can (and undoubtedly do) conceive at any time of the year. However, researchers have found patterns in human births where some periods of the year see more baby ejections than others.

Therefore, by definition, we do have a mating season.

So which months are we getting all up close and personal?

The Office for National Statistics found births surge towards the end of September and early October, with September 26th being the most popular day to be born (in the UK). So if you count back 9 months, where does that land you?

That’s right, slap bang on the Christmas period.

Why Christmas?

Well the free-flowing booze and an excuse to cuddle up certainly allows for some festive fooling around. But also, a study published in the Journal of Obstetrics and Gynecology suggested that (biologically) winter gave greater success for baby-making. The lower temperatures allow men to produce higher quality sperm. Meanwhile, shorter daylight time creates a more receptive ovum (where the eggs are stored), therefore increasing conception.

Interestingly, whilst December is the highest conception time, it’s also the lowest birth period

Source: Birth registrations in England and Wales



So why don’t we just have a breeding season?

When it comes down to it, we don’t really need one.

The first primitive primates we evolved from 55 million years ago dwelled in tropical climates; the harsh winters that most seasonal breeders avoided never affected us. Then by the time we moved into harsher climates, we had already developed the technology to insulate ourselves from the variability of our environment. Therefore, our offspring were less vulnerable to the external environment. Which is just as well really as our very long infancies meant our children would experience a full years worth of climate variation anyway, regardless of when they were born.

However, if we did become seasonal breeders…

Let’s face it, our lives would certainly be made easier. We could have company shutdowns occur during our breeding months where we focus solely on finding the perfect mate. A national speed date for all singletons if you like. Then once all was done and dusted, the rest of the year’s energies could be focused on frontin’ and maxin’ in the car you spent all day waxin’.

No more wasted hours spent confused whether Andrew is still interested based on that one text he sent without his usual winking emoji. Or agonizing over whether Tabitha is really a vegan or whether she’s just excusing herself from that ice cream date you asked her out on. We’d save a lot of time if women just made it biologically obvious that they were interested in baby-making.

After all, this is what many of our primate cousins do.

The females of most primates make it apparent when they are in heat, usually via genital swellings, behaviors, and vocal noises that indicate ovulation and sexual receptiveness.

However, human females have concealed their ovulation.

In fact, they’ve done such a good job that a study published in the American Journal of Human Biology concluded that most women cannot detect their own ovulation. They realised this upon finding only 28% of U.S. women (who believed they knew when they ovulated) were actually correct.

In which case, you’d think the men among us would also have very little chance of guessing.

However, an interesting study by renowned psychologist Dr. Geoffrey Miller discovered a curious fluctuation in the amount of tips that were given to lap dancers depending on where they were on their menstrual cycle. Lap dancers earned on average $150 (£105) more per shift when they were ovulating compared to when they were menstruating. An 81% increase!!

Unsurprisingly, dancers who were on the pill didn’t see the same increase, as the hormonal contraceptive creates a constant state of ‘pretend’ pregnancy (removing the very fertile time that changes behaviour). In fact, these dancers earned $80 (£55) less than non-pill users (regardless of cycle stage).

So what female cues are men unconsciously picking up on???

To summarise the research, when women are most fertile they are more likely to:

*But why do they wear more red?

Ripe fruit.

Our first ancestors who evolved the superior quality to detect the colour red gave themselves a huge advantage when finding ripe fruit. These red-detecting genes were then passed on to become an integral part of our nature. Eventually, we became hardwired to associate red as reward.

To this day, the colour red is known to quicken the heart rate making us feel excited or “out of breath”. So it’s no surprise that we evolved to associate it with sex. Over time, this attractive colour that allured men then shifted to our faces, mainly concentrated at the lips. The use of lipstick has been dated right back to the Egyptians, Romans and the Greeks who used wine and dyes to tinge their lips. This was to intensify the natural swelling and reddening that our lips undergo when we become sexually excited[2].

So basically, both men and women come to resemble fruit in an attempt to attract each other.

I don’t think Violet has quite the right idea

Better yet, women can actually use this in a practical way to their advantage. A study by Nicolas Guéguen discovered male drivers more likely to offer a ride to women wearing red than when compared to wearing any other colour.

Now, this may sound like a shallow reason for men to base the decision of whether to give a lift or not, however, do not assume this gives evidence for why men are more likely to be the unfaithful one in a heterosexual relationship. Worryingly, during their most fertile stage, women were found to become especially attracted to men who weren’t their primary partner.

Now this sends us down the rickety path of our questionable monogamy and its roots. Are we supposed to be monogamous?

Well with the exception of the Gibbon, all of our ape-relatives practice polygamy.

However, human females soon put an end to that with a little trick called concealed ovulation. As mentioned before, concealed ovulation supposedly made it difficult for men to know when a woman was at her most fertile stage during menstruation.

So why have women evolved this unique concealed ovulation?

What are they trying to hide? (Besides the obvious).

In layman’s terms, it is a mechanism to get more out of their man/men, (regardless of whether they were already a strong independent woman).

Concealed ovulation demands men to invest, behave and give extra meat (hunted game meat that is).

The reasons for concealed ovulation (acquired from Dr. Schoröder’s article):

Male Investment – As our heads grew bigger , and our babies grew more needy with longer maturation times, it became mutually beneficial for the man to remain interested in the woman. The woman therefore concealed her evolution to ‘trick’ him into assuming constant ovulation. As a result, mating throughout the entire menstrual cycle created a pair bonding effect that (usually) ensured the man to invest resources for both mother and child.

Making men behave – The creation of a competitive breeding frenzy that usually occurs during a breeding season can be diminished by making ovulation always seem available. Supposedly, this would stop men fighting each other so much.

Getting free food – You know when you’re in a club and a girl comes up to you acting all single so you buy her a drink but then you later see her again just chilling with her boyfriend Chad acting like she doesn’t know you? Well, that’s a little trick that women have perfected over hundreds of thousands of years. Replace drinks with freshly hunted game and you can see why concealing ovulation could make a man give her extra meat (compared to an obviously “off heat” and therefore sexually unavailable woman).

Bipedalism, the ultimate game changer towards concealed ovulation!!!

As we ventured out into the savannah, the scary lions and hungry hungry hippos got us all a bit horrified. So our small communities came closer together meaning we lost the need for the woman’s long-distance sexual cues, e.g. mating calls and genital swellings. This aligned with our new erect postures which changed the position of the female external genitals and concealed them between the legs; thus genital swelling as a way of signaling became redundant[3].

More monogamy…

Finally, another trick women use to ensure a loyal mate is synchronised ovulation. The purpose of this is believed to prevent the monopolisation of all females by one alpha male. If all females become ‘available’ simultaneously, one male will be unable to mate with all of them meaning other males will have the opportunity pass on their genes and to find a wifey, (increasing monogamy)[4].

Synchronised or not, I reckon this guy could still juggle multiple women

So all in all, with such a hypersexual species, mother nature soon realised:

Concealed Ovulation=Constant Breeding/Pair Bonding =Monogamy=No need for Breeding Season

Simple, right?

If only real life relationships were as simple as this equation.