VALENTINE'S DAY & THE BIRTH TIMING

Oooh hallo dear English hearing visitor, welcome back to me, @sciencemug, the blog/twitter account/podcast which speaks to you in Eng?ish a language that is to real English what the new Twitter timeline is to something someone really wants. Aaand that does it using the voice of a dumb human controlled via a wireless-voodoo trick. Aaaand that tells you mesmerizing science stories while, at the same time, is writing a manual about how to survive in case a pandemic of the “camomile virus”* ravage the world letting all the infected in a deep state of calm and serenity so that you suddenly find yourself in the dire situation of not having anymore anyone to fight with about how overrated and useless “Gravity” is aaaand also about your weird theory according to which “gluten free pasta” means that gluten -after corrupting pasta guards with an autographed picture of the juicy "Miss Tomato 2015" and some basil’s leaves- well, it, the gluten, manages to break free from the pasta prison and now lives, disguised as a protein bar for crossfit maniacs, in a minimarket in South Carolina.

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Weeeel this time, dear listener, you’ll hear a 2011 story appeared on the journal Social Science & Medicine. The story's about how on Valentine’s Day [the phoniest, most artificial and trivial of all the fake festivities of the world (and that’s why the dumb human created a collection of love products right for the occasion and even wrote a love e-book!)] there’s a sensible increase of child births.

- Valentine's Day post 2019 -
- Valentine's Day post 2013 -

by sNg & @sciencemug

The story goes like that. Professor Becca R. Levy, Pil H. Chung and Martin D. Slade are scientist of the School of Public Health of Yale, and they think “cultural representations, in the form of salient holidays” (Levy et al, 2011 (P)) can influence birth timing. They in fact predict that, on Valentine’s Day, spontaneous, cesarean, and induced births would peak because this day is associated with positive feelings and events like “love, flowers” (P) and the rest of the cheesy stuff (and even if the researchers don’t mention it, well, chocolate too must be one huge deal in all this births story).
 
On the contrary, then, the Becca’s science-gang foresees a decrease in spontaneous and non spontaneous births on Halloween, ‘cause of the negative associations linked to this festivity (like witches, skeletons, death, ghosts, bad movies, not so bad movies, candy induced gain of weight, candy induced dentist bills and so on and on).
 
So the Becca’s trio digs into a specific dataset. This dataset is stuffed with all the birth-certificate informations of the United States in the week before and after Valentine’s Day and Halloween in the decade between 1996 and 2006 (as Becca&co explain in the paper, they stop in 2006 ‘cause “2006 [is] the most recent data year available from the National Center for Health Statistics at the time of [their] study in 2010” (P). 
And we’re talking of big numbers here as you can imagine dear listener: almost 1 million and 7 hundred thousands births during the Valentine’s Day window, and over 1 million and 8 hundred thousands births during the Halloween’s one.
 
Soo, what  do the scientists find?
The answer after the break. 
 

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by sciencemug

 

You’ll share the wellness that only munching chocolate can give you with what only bufotenin can offer, that is a wide range of vivid hallucinations among which, statistic says, you should also find a romantic one.
“Chocotenin”, and your Valentine’s Day will reach a whole new level of sadness!

(“Chocotenin” is also available in the form of candy bars for Halloween, eggs for Easter and whatever you want for whatever occasion/day you need it). 

 
So what do professor Becca’s and her science associates find out after checking the dataset of births in the US in correspondence of the two weeks centered on Valentine’s Day and Halloween from 1996 to 2006?
 
Weell, dear listener, the researchers find out that they are right, namely that on V-day, as respect to the week before and the one after it, births go up overall by 5%. More precisely the increase is of the 3.6% for spontaneous births, 12.1% for cesarean, and 3.4% for induced births.
 
As foreseen, besides, on Halloween the trend is
the opposite, with a decrease of the 11.3%: 5.3%, 16.9%, and 18.7% for spontaneous, cesarean, and induced births respectively.
 
If you like numbers, dear listener, the above mentioned  percentages can be translated like that: as for Valentine’s Day, there is “a yearly average of 234 more spontaneous births […] 353 more cesarean births […] and 58more induced births […] than the other days in the window” (P).
As for Halloween there’s “a yearly average of 351 fewer spontaneous births […] 508 fewer cesarean births […] and 359 fewer induced births […] than the other days in the window” (P).
 
Moreover the three researchers make their statistical analysis also using only the sub data-sets of the women belonging to the two major US minorities (i.e. African-American and Mexican-American). They do it to verify if the birth trend be the same and therefore the finding about V-day and Halloween cultural influence on birth timing be generalizable.
And the Becca’s research trio finds that the results of this second sub-analysis match with the previous ones (“Valentine’s Day increased overall by 9.1% […] Halloween decreased overall by 7.1%.” (P))
 
The conclusion, scientists say, is that “[a]s predicted, the number of spontaneous and cesarean births show[s] a statistically significant peak on Valentine’s Day, and the number of spontaneous, cesarean, and induced, births show[s] a statistically significant dip on Halloween.” (P)

The discovery pushes toward the possibility that women can anticipate or delay “births, within a limited time frame, in response to cultural representations” (P) that somehow manage to “influence the hormonal mechanism that controls birth timing” (P).
 
In other words, dear listener, V-day is the day of love and affection. This heart-shaped love-scented mood may trick women into thinking that Valentine’s Day is a very propitious day for a baby to get into this world, and this cultural induced thought can trigger the hormonal cascades that actually make the birth happen.
 
As for Halloween, well, it’s a happy day for children, so why the bad influence on births?
Well, Becca and colleagues say that “in late pregnancy, women tend to experience heightened psychological vulnerability, particularly to anxiety” (P) and this can enhance the skeleton-witches-ghosts-death cultural state of mind that frames the festivity, and make women think that Halloween is not a good day for a baby to get into this world. Hormones do the rest, and the delay is served.
 
Ok, you say, dear canny listener, but why on Earth three researchers of one of the most important universities of the world spend time on a huge dataset to see if cultural stereotypes influence birth timing?
 

The back of a cultural stereotype called pumpkin AKA Jack-o'-lantern (by @sciencemug)

[The pumpink's pic is a Public Domain image adapted by @sciencemug (source: wikia.com)]

Well, listener, they do it because their previous research shows that cultural stereotypes can influence the well being of persons. A Becca’s et al study done in 2002 on 660 people aged 50 and older finds indeed that elders that think of ageing in a positive way live up to 7 and a half years longer than those who have a negative self perception of ageing (1). 

Thus professor Becca has already evidence that cultural factors do impact human biology. So why culture could not impact birth timing too?
 
Besides a 2003 study on Taiwanese women proves that the rates of cesarean procedures are linked to the classification as auspicious or inauspicious of the days of the year according to the “traditional Chinese cosmological interpretations of the lunar calendar” (2).
 
So, dear listener, got why the Becca’s Yale trio does the research on Valentine’s Day and Halloween? Ok. Now, since I know you are thinking it, why don’t you let go and you scream it? Ok? Ok! GO!
WHHHHHHYYYYYYYYYYYYY? Why three scientists think that knowing that cultural stereotypes can influence birth timing is something relevant to humanity?
 
Weel, dear listener, first because these researchers are supporters of the biocultural studies, that is a discipline which includes “social, cultural and behavioural variables in the research design” (3) and that aims to create useful models to study the “interface between bilogical and cultural factors affecting human well-being” (3).
And second ‘cause… Well, as usual, let’s hear what the researchers say on it: “[o]ur findings indicate the need to adapt obstetric staffing on Valentine’s Day and Halloween to the respective peaks and dips of births. In the case of increased […] cesarean procedures on Valentine’s Day, these adjustments might extend to planning for: the longer hospital stays they entail; the greater risk of infants’ respiratory problems; and, if pregnant women previously had the procedure, the greater risk of complications.”(P)

In short, the more you know about what can influence the birth timing, the better you can prepare to face the events, the safer moms and babies in the end are.
 
Alright? Good!
 
I’m not gonna say it, no no, I’m not gonna say Happy Valentine’s Day. No! Even the dumb human agree on this.

Ciao!



*
Don't you worry dude, just messing up with your latent hypochondria...


The paper this post is about (P)
- Levy, B. R., Chung, P. H., and Slade, M. D. (2011). Influence of Valentine's Day and Halloween on birth timing. Soc Sci Med 73, 1246-1248.

Bibliography
1- Levy, B. R., Slade, M. D., Kunkel, S. R., and Kasl, S. V. (2002). Longevity increased by positive self-perceptions of aging. J Pers Soc Psychol 83, 261-270.
2- Lo, J. C. (2003). Patients' attitudes vs. physicians' determination: implications for cesarean sections. Soc Sci Med 57, 91-96.
3- McElroy, A. (1990). Biocultural Models in Studies of Human Health and Adaptation. Medical Antropological Qaurterly 4, 243-265.