Speaker 1: Welcome to Brainstuff, a production of iHeartRadio. Hey brain Stuff.
Speaker 1: Lauren vogelbamb here. It may seem as if you're buying
Speaker 1: a lot more birthday gifts at certain times of the year,
Speaker 1: But why is this? Is it your imagination or are
Speaker 1: there really more babies born in specific months or on
Speaker 1: specific days. If you look at births in the United
Speaker 1: States from the twenty year period between nineteen ninety four
Speaker 1: and twenty fourteen, a really clear pattern emerges. There were
Speaker 1: an average of over six thousand to over twelve thousand
Speaker 1: babies born on any given calendar day, but nine out
Speaker 1: of the most ten common birthdays fell in September, with
Speaker 1: the one outlier in July. A. September ninth was the
Speaker 1: most common birthday during that time, with an average of
Speaker 1: twelve thousand, three hundred and one berths on that day
Speaker 1: every year. The rest of the dates range from September
Speaker 1: ten through the twentieth, with September eleventh and the thirteenth
Speaker 1: conspicuously missing. The July date is July seventh, But okay, why?
Speaker 1: The short answer is that nobody knows for sure, and
Speaker 1: it's a question that's veritably plagued researchers for over a century,
Speaker 1: but there are some pretty credible hypotheses. First, a, people
Speaker 1: may have extra free time and be feeling extra celebratory
Speaker 1: during the year end holiday season, which happens to be
Speaker 1: about nine months before all of those September birthdays. There
Speaker 1: are a lot of parties going on, which often come
Speaker 1: hand in hand with alcohol consumption, tending to lower inhibition
Speaker 1: and increase sexual behavior. Plus, people usually have time off
Speaker 1: from work over the holidays. A study is shown that
Speaker 1: people have more sex on the weekends and over holiday periods,
Speaker 1: and it's not just in the United States. A birth
Speaker 1: seasonality has been observed around the world. One as yet
Speaker 1: non pure reviewed study of data from a reproductive health
Speaker 1: tracking app combined with birth records found that people's fertility
Speaker 1: seems to peak right around the winter solstice in both
Speaker 1: the northern and southern hemispheres. Interestingly, other studies have shown
Speaker 1: that at higher latitudes that is further away from the equator,
Speaker 1: where temperatures get colder earlier in the year, have fertility
Speaker 1: rates that peak earlier closer to the autumn equinox. Closer
Speaker 1: to the equator, where temperatures stay warmer longer, fertility rates
Speaker 1: peak later, a closer to the spring equinox. There could
Speaker 1: be multiple factors at work here, from caloric intake and
Speaker 1: exercise strain during different seasons, to the sheer fact that
Speaker 1: in the cold, dark months people spend less time outside,
Speaker 1: leaving more time for indoor activities like canoodling. However, research
Speaker 1: has shown that in the US, peaks in birth rates
Speaker 1: across the calendar year have been evening out over the
Speaker 1: past seventy years or so, a meaning that births are
Speaker 1: less clustered around certain seasons. It's now more likely to
Speaker 1: have a baby any day of the year. But within
Speaker 1: that twenty year period from nineteen ninety four to twenty fourteen,
Speaker 1: there were, of course least common birth dates. The very
Speaker 1: least common was December twenty fifth, widely celebrated as Christmas Day.
Speaker 1: On average, six five hundred and seventy four babies were
Speaker 1: born each year on that day during the study period.
Speaker 1: You can chalk this one up to the sheer number
Speaker 1: of pre scheduled sea sections and inductions that we do
Speaker 1: these days, and not too many doctors, midwives, or impending
Speaker 1: parents really want to spend that holiday in the hospital
Speaker 1: unless they don't have a choice. About it. I, for one,
Speaker 1: really wrecked my parents' morial day plans when I showed
Speaker 1: up a couple weeks early, though they said it was
Speaker 1: worth it. The rest of the least common birthdays were
Speaker 1: also centered around holidays Christmas Eve and the day after Christmas,
Speaker 1: New Year's Day, and the day after July fourth, Halloween,
Speaker 1: and right around Thanksgiving November twenty third, twenty fifth, and
Speaker 1: twenty seventh. Even February twenty ninth, a date that only
Speaker 1: comes around once every four years during leap years, was
Speaker 1: still a more common birthday than any of these were,
Speaker 1: with an average of over ten thoy four hundred births.
Speaker 1: Perhaps parents aren't wary about that date for the reasons
Speaker 1: that they may be wary about those others, or maybe
Speaker 1: they enjoy the novelty cue lots of jokes about being
Speaker 1: only seven years old on one's twenty eighth birthday, for example.
Speaker 1: These changing trends show how much medical care has changed
Speaker 1: in the past one hundred years, making people healthier year
Speaker 1: round and giving us more options in when to be
Speaker 1: pregnant and when and how to give birth. Today's episode
Speaker 1: is based on the article what are the most and
Speaker 1: least popular birthdays in the United States on HowStuffWorks dot
Speaker 1: Com written by leoh Hoyt. Brain Stuff is production of
Speaker 1: iHeartRadio in partnership with how Stuffworks dot Com and is
Speaker 1: produced by Tyler Klang. Four more podcasts to my heart Radio,
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