Kiddushin 25a ~ Polydactyly

This is the first of two posts for Kiddushin 25 which will be studied on Thursday September 7th.

קידושין כה, א–ב

 א"ר חייא בר אשי אמר רב היתה לו יתרת וחתכה עבד יוצא בהן לחירות, אמר רב הונא והוא שנספרת על גב היד

Rav Hiyyah bar Ashi said in the name of Rav: if a slave had an extra finger and his master cut it off, the slave is freed on account of this act. Rav Huna said this only applies if the extra finger is in line with the others [lit. counted alongside the hand].  

Polydactyly (from the Greek daktylos, meaning finger), is a developmental abnormality in which there are more than the customary five fingers or toes at the end of the arms and legs. It has long been recorded in ancient civilizations - and is even mentioned in our own Hebrew Bible. Do you know who is described there as having a total of twenty four fingers and toes? (Click here to find out.)

Polydactyly is classified by the location of the extra digit: If it is found on the thumb or big toe, it is called preaxial polydactyly. If it is found on the the little (fifth) finger or toe it is called postaxial polydactyly.  Accessory digits in-between are classified according to their location and where they join the hand or finger. Syndactyly, on the other hand (!) occurs when there are fewer than five fingers or toes on each limb. (We will discuss syndactyly when we study tractate Bechorot, (daf 45a), on November 2nd 2026,  הבעל"ט.)

Rav Huna's Classification, and Swanson's classification

There are many different ways to classify polydactyly - although the most commonly used is the 1964 Swanson classification system, a modified version of which was adopted by the American Society for Surgery of the Hand and the International Federation of Societies for Surgery of the Hand in 1976. 

But Rav Huna, who died in Babylon around the year 296 CE, developed his own classification system long before Swanson, and it is based on simple observation: does the extra digit seem to begin in line with the other fingers, or does its origin seem to lie above them?  For Rav Huna, an extra digit that originated beyond the metacarpal-phalyngeal joint (the knuckle for our non-medical reader) in the hand, or beyond the metatarsal-phalageal joint in the foot did not have the legal status of a normal digit.  So an act of assault by the owner of a slave in which this kind of digit was amputated would not legally count as sufficient cause to allow the slave to gain his freedom.  With this information, look at the drawings below and decide in which case the loss of the extra digit would be sufficient cause for the slave to be freed.

Various forms of postaxial (ie. not on the big toe) Type A polydactyly of the foot, ranging from a partially duplicated fifth intermediate phalanx (top left) to a fully developed sixth digit, including the metatarsal (bottom right). From Case DT. Hill RJ. Merbs CF. Fong M. Polydactyly in the Prehistoric American Southwest.  Journal of Osteoarchaeology 2006: 6: 221–235.

If the slave had an extra fifth toe outlined in Figures 2-6, its loss would result in the slave going free. In all these cases, the extra digit arises in line with the base the the other toes (and in Figure 6, the extra toe is joined to an extra metatarsal). But in Figure 1, the extra fifth digit arises from the distal end of the fifth distal phalange (or, for our non-medical reader, the tip of the pinky); in this case its traumatic amputation by the slave's owner would not result in the slave gaining his freedom. 

This categorization appears to be another previously unrecognized medical first in the Talmud: Rav Huna's classification of polydactyly.   

“היתה לו אצבע יתירה וחתכה, אם עומדת בסדר האצבעות יוצא לחירות ”

— שולחן ערוך יורה דעה הלכות עבדים סימן רסז סעיף כט

Polydactylous feet from Newspaper Rock in Indian Creek State Park, Utah. These carvings in rock are called petroglyphs, and were made by native Americans as long as 1,500  years ago.

Kiddushin 16b ~ Measuring Puberty

קידושין טז, ב

בן תשע שנים שהביא שתי שערות שומא מבן ט' שנים ויום אחד עד בן י"ב שנה ויום אחד ועודן בו שומא ר' יוסי בר' יהודה אומר סימן בן י"ג שנה ויום אחד דברי הכל סימן 

If a nine year old grows two hairs [in the pubic region] the growth should be attributed to a mole [and not as a sign of sexual maturity]. [If these hairs grow] from the age of nine years and one day until twelve years and one day, and they are still there [when the child reaches twelve, one opinion is that they should be attributed to a] mole, and Rabbi Yossi bar Rabbi Yehuda says they are a sign of sexual maturity. [If these hairs grow] when the child is thirteen years old and one day, then everyone agrees they are a sign of sexual maturity...(Kiddushin 16b)

Pre-Modern Descriptions of Puberty

The way in which children develop into adults has fascinated us for centuries.  In fact, the earliest surviving statement on human growth dates back to the sixth century BCE, (not long after the prophet Jeremiah lived) and is by the Athenian poet Solon. One critic described his poem as combining "scientific sense with philosophical probability (if not, regrettably, with poetic elegance)." Here is Solon:

A young boy acquires his first ring of teeth as an infant and sheds them before he reaches the age of seven years. When the god brings to an end the next seven year period, the boy shows the signs of beginning puberty. In the third hebdomad, [ a period of seven years] the body enlarges, the chin becomes bearded and the bloom of the boy's complexion is lost. In the forth hebdomad physical strength is at its peak and is regarded as the criterion of manliness; in the fifth hebdomad a man should take thought of marriage and seek sons to succeed him. In the sixth hebdomad a man's mind is in all things disciplined by experience and he no longer feels the impulse to uncontrolled behavior. In the seventh he is at his prime in mind and tongue and also in the eighth, the two together making fourteen years. In the ninth hebdomad, though he still retains some strength, he is too feeble in mind and speech for the greatest excellence. If a man continues to the end of the tenth hebdomad, he has not encountered death before due time.

Hippocrates believed that puberty could be delayed in areas where "the wind is cold and the water is hard". Rabbi Shimon ben Gamliel (d. 70CE) would have agreed, because he thought that the growth of pubic hair was hastened in those who used the bathhouse regularly.  But it is especially interesting to compare Aristotle's writings on puberty with those of the Talmud (which of course were codified several hundred years later).

In man, maturity is indicated by a change in the tone of the voice, by an increase in size and an alteration in appearance of the sexual organs, and also by an increase in size and alteration in appearance of breasts, and above in the hair growth above the pubes.

Aristotle (d. 322 BCE) seems to have put a lot of weight on the growth of pubic hair, just like the rabbis of  in the Talmud did many years later. Galen, who died in 199 CE, was cautious about timing the onset of puberty: "Some begin puberty at once on the completion of the fourteenth year, but some begin a year or more after that" (De Sanitate Tuenda, or p288 of this translation). Jumping forward several centuries, we find that girls in Tuscany in 1428 were allowed to marry aged eleven and a half, although they were forbidden to live with their husbands until they were twelve. However the Bishop of Florence (later canonized as Saint Anthony) declared that cohabitation was allowed "provided the girl had reached puberty." 

The Tanner Scale

Today, the stage of sexual maturity in children is most commonly measured using the Tanner scale, described by the British pediatrician James Tanner, who died in 2010.  (He wrote a fascinating History of the Study of Human Growth as a sort of a hobby, but his day job was working as a Professor at the Institute of Child  Health in London.)  Here is how Tanner described his scale in boys, (from his original paper published in 1970):

Stage 1: Pre-adolescent. The velus [sic] over the pubes is no further developed than that over the abdominal wall, i.e. no pubic hair.

Stage 2: Sparse growth of long, slightly pigmented downy hair, straight or slightly curled, appearing chiefly at the base of the penis. This stage is difficult to see on photographs, particularly of fair-headed subjects...

Stage 3: Considerably darker, coarser, and more curled. The hair spreads sparsely over the junction of the pubes. This and subsequent stages were clearly recognizable on the photographs.

Stage 4: Hair is now adult in type, but the area covered by it is still considerably smaller than in most adults. There is no spread to the medial surface of the thighs.

Stage 5: Adult in quantity and type, distributed as an inverse triangle of the classically feminine pattern. Spread to the medial surface of the thighs but not up the linea alba or elsewhere above the base of the inverse triangle.

“There has been less discussion in the literature as to whether the appearance of pubic hair has advanced in females, although this does seem to be the case, pubarche having advanced by at least 6 months. The PROS study found stage II pubic hair to be apparent in African-American females at a mean age of 8·78 years and 10·51 years in whites.”

— Slyper, AH.The pubertal timing controversy in the USA, and a review of possible causative factors for the advance in timing of onset of puberty. Clinical Endocrinology (2006) 65, 1–8

Tanner also described other signs of sexual maturity, since growth of pubic hair is not the only maker.  In boys, for example, Tanner used a five-stage system for genital growth: in stage one, the  "testes, scrotum, and penis are of about the same size and proportion as in early childhood," whereas in stage two, "the scrotum and testes have enlarged and there is a change in the texture of the scrotal skin..."  Tanner noted that the stages of pubic hair development and the stages of genital development differ, so that a boy may reach full genital maturation sooner than he reaches stage five on the pubic hair scale.  

From Marshall A. Tanner JM. Variations in the pattern of pubertal changes in boys. Archives of Disease in Childhood 1970. 45: 13-25.

Tanner's work reveals what we already know intuitively. Maturity, whether sexual or emotional, is a process that takes time and proceeds through many stages. The rabbis of the Talmud relied predominantly on one marker of adulthood:  sexual maturity as evidenced by a minimal of pubic hair growth.  But they used it in conjunction with the age of the child.  They also understood that the onset of these signs might be sooner in some children and later in others.

Sequence of events in puberty in girls (top) and boys. From Marshall A. Tanner JM. Variations in the pattern of pubertal changes in boys. Archives of Disease in Childhood 1970. 45:22.

In most European countries, the age of the onset of puberty (as measured by the onset of menstruation) has fallen by about a year per century. Boys also seem to be developing earlier than previously, possibly by more than a year. Data from the US National Health and Nutrition Examination Survey (NHANES III) study of boys aged 8 –19 years, suggests that the mean age of onset of male genital development based on visual inspection is now about nine years for African-Americans and ten years for white boys.

Another First?

Last year we analyzed talmudic statements of R. Hiyya (who lived in the second half of the second century,) and Rava, (d. 350CE) who appear to have been the first to report an association between obesity and delayed puberty in boys.  They claimed that puberty may be delayed in boys who are underweight, and this association has now been confirmed. As we noted then, none of the researchers has credited these talmudic sages for being the first to notice these associations. But Rava and R. Hiyya were first, and firsts count for something in science. The Baraita in today's daf  may be the first recorded discussion of the lower limits of sexual maturity. But the rabbis of the Talmud used other markers of maturity, like breast development which is discussed in Masechet Niddah (47a).They distinguished between "lower" and "upper" signs of puberty, and so presaged the work of Tanner. (The rabbis also ruled that "all girls who are examined are examined by women". Thank heavens.)

There were several reasons why the Talmud had to codify the stages of physical maturity.  Among these were to allow a father to decide to whom his daughter would marry.

A father who declares...my daughter is twelve years and a day is believed in order to marry the child off...(רמב׳ם הל׳ אישות ב:כג)

Today, any notion that a child under the age of twelve (or sixteen for that matter) would be mature enough to marry is utterly repugnant to us. But according to the UN in developing countries, one in every three girls is married before reaching the age of eighteen, and one in nine is married by the age of fifteen.  When we read the Talmud we often get a glimpse into a Jewish world very different from our own. But some practices of that world still exist outside of the Jewish community today, to the shame of us all. 

From United Nations Children’s Fund, Ending Child Marriage: Progress and prospects, UNICEF, New York, 2014.

Kiddushin 12b ~ The Surprising Birth of Rebbi Chiyyah's Twins

Today’s page of Talmud continues an analysis of the fluctuating value of a perutah, the minimum amount that a man must pay to purchase his wife. For reasons that need not detain us, Rav Chisdah mentions a strange fact about Yehudit, the wife of the Rebbi Chiyyah:

קידושין יב, ב

לָאו הַיְינוּ דִּיהוּדִית דְּבֵיתְהוּ דְּרַבִּי חִיָּיא, דַּהֲוָה לַהּ צַעַר לֵידָה

Rav Chisdah explained: Is this not similar to the case of Yehudit, wife of Rabbi Chiyyah, who would have painful childbirths [and therefore wished to leave Rabbi Chiyyah]?

Elsewhere in the Talmud, (on a page that we will study on April 22nd, 2027,) there is more detail about one of Yehudit’s pregnancies. When I first read the story, I considered it to be entirely fanciful. It was impossible, so it seemed to me, to have actually occurred. Then I read the science, and I changed my mind. Let’s see if it changes yours. So let’s take a look at Niddah 27a:

Yehudit’s Special Twins

נדה כז, א

א"ר אבין בר רב אדא אמר רב מנחם איש כפר שערים ואמרי לה בית שערים מעשה ונשתהה ולד אחד אחר חבירו ג' חדשים והרי הם יושבים לפנינו בבית המדרש ומאן נינהו יהודה וחזקיה בני רבי חייא

Rabbi Avin bar Rav Adda says that Rav Menachem of the village of She’arim, and some say that he was from Beit She’arim, says: An incident occurred where one offspring remained in the womb after the other was born for three months, and both twins are sitting before us in the study hall. And who are they? They are Yehuda and Chizkiyya, the sons of Rabbi Chiyyah.

Delayed Interval births - what you need to know

When you look at the medical literature, it turns out that there are many case reports of delayed-interval twin births. This is probably because the number of multiple pregnancies has increased due to the expansion of assisted reproductive technology. In nearly all, the first twin died soon after delivery because it is too premature to survive.

Here is just one example. In 2019 a group from the Department of Clinical and Experimental Medicine at the University of Pisa in Italy published a case report with a very lengthy title: Delayed delivery of the second twin: Case report and literature review of diamniotic dichorionic twin pregnancy with very early preterm premature rupture of membranes. A mother went into very early labor and delivered the first of two twins at about 26 weeks’ gestation. The second twin remained in her uterus, and was delivered 29 days later by cesarean section. The first very premature twin died, but happily the second survived and at 6-month follow-up, “no neurological, cardiac or other defects could be detected.”

A 2016 systematic review found 13 articles reporting a total of 128 cases of delayed-interval twin births. It reported that the second born twin had a significantly lower mortality risk compared to the first born (relative risk = 0.44, 95% confidence interval = 0.34 – 0.57, P<0.0001,) which makes sense since the second twin had the benefit of a longer period of uterine gestation.

Results of individual studies, mortality of the second born versus the first born. From Feys S. Jacquemyn Y. Delayed-interval delivery can save the second twin: evidence from a systematic review. Facts Views Vis Obgyn, 2016, 8 (4): 223-231.

Interval twin births - the world Record

There is even an official world record for delayed-interval twin births. According to Guinness World Records, the longest verified interval between the birth of twins is 87 days (and 1 hour 45 minutes). Twin girls Amy Ann and Kate Marie Elliot were born 87 days apart, at Waterford Regional Hospital in County Kilkenny, Ireland. Amy was born prematurely on 1 June 2012 and Kate followed on 27 August. Because Amy Ann was born at 09:16 and Kate Marie at 11:01, the exact interval is 87 days, 1 hour and 45 minutes. That’s a little shy of three months. Just like the story in the Talmud.

Actually, there is a report that in 2018 this record was beaten, though I’d be careful about believing what you read in perhaps the smuttiest paper in Britain, The Sun. But here it is anyway. And note that the twins were born just over three months apart.

Mum Oxana went into labour initially at just 26 weeks pregnant and gave birth to Liana prematurely on November 17, 2018. She weighed just 2lbs. Three months later, she finally gave birth to Leonie - four days after her initial due date. A spokeswoman for Holweide hospital in Cologne said: "After the birth of the first twin, the cervix closed again and the unborn sister could remain in the womb.” As contractions ceased, doctors decided that Oxana could carry her second baby girl to term.

Maternity chief Dr Uwe Schellenberger said: "The conditions were very good as well due to the existing second placenta and we wanted to try to let the second child mature as long as possible in the womb." Leonie was born a total of 97 days difference with her twin sister Liana and was born weighing 8.1lbs. Dr Schellenberger said: "It's also a rare case for our maternity clinic, but it was not the first time that twins were born on different days at the Holweide hospital. "But the time difference of 97 days is unique for us and also special worldwide."

According to the hospital, the girls may have broken a world record. "Such a 'two-time twin birth' is very rare worldwide," the spokeswoman explained. "According to our own research, twins with a time difference of 87 days were born in Ireland in 2012." Liana spent her first few weeks in a neonatal care unit at the hospital where she stayed until she was strong enough to go home.Both girls now weigh around 12.5lbs and have developed well.The spokeswoman said that they've both been reunited at their family home and are set to grow up healthy.

What would it have taken for Yehuda and Chizkiyya to survive?

In its English translation, the Artscroll Talmud introduces this story in Niddah as a “fantastic incident.” If by “fantastic” it means “based on fantasy” or “not real,” it this commentary is mistaken. If however, it means “so extreme as to challenge belief,” well, then it is correct. It is indeed an extremely unlikely story, but not an impossible one. Here is what it would take for the story of Yehudit and her twins to have actually occurred.

1. The first born twin would have had to be born at around six months gestation. Even today, with neonatal intensive care units, incubators, respirators, antibiotics and specialist staff, this is the very limit of survivability. The mortality rate in babies born between the 23rd and 25th week is 32%.

2. Next, Yehudit, the mother, would have had to survive the preterm premature rupture of the amniotic membranes which carries a risk of 17-52% of introducing an intrauterine infection, and a risk of 4-22% of causing maternal sepsis.

3.Then Yehudit would have had to carry the second twin to a full-term birth, and that twin must survive.

4. Finally - and this is important - the Talmud lets us know that the boys were “sitting in the study hall.” In other words, they both had a fairly normal cognitive ability, which in very premature infants is often not the case.

Tosafot Agrees - it is really rare

The chances of all this happening are very low. In fact the medieval compendium of commentaries on the Talmud known as Tosafot makes this very point (Niddah 26b ד’ה ילדה):

ילדה ואח"כ הפילה שליא אפי' עד י' ימים אין חוששין לולד אחר. אע"ג דאמר לקמן דנשתהא הולד שלשה חדשים מ"מ לא שכיח וכל כמה דלא חזינן לא חיישינן

Even though the Talmud states that “one offspring remained in the womb after the other was born for three months,” this is not common. And when something is so rare that it almost never happens, it may [for practical purposes] be ignored.

But a very low likelihood of something happening does not make it impossible. The three month delay in the birth of the boys was indeed scientifically possible. I hope Yehuda and Chizzkiya realized just how lucky they were.

““We feel so blessed to be here,” their mother said. “The only thing that’s gotten me through this... is to say, ‘God is in control,’” she noted.
”

— Kristen Miiler, mother of twins born five and a half weeks apart. See "Doctors stunned by rare twins born more than five weeks apart." Washington Post April 7, 2016

Kiddushin 7a ~ Does Marriage Make You Happier?

קידושין ז, א

אמר ריש לקיש: טב למיתב טן דו מלמיתב ארמלו

Resh Lakish said: It is better for a woman to live as tad du than to live alone...

In a 1975 lecture to the Rabbinical Council of America, Rabbi J.B. ("the Rav") Soloveitchik,  quoted the aphorism of Resh Lakish found in today's page of Talmud.  The Rav went on to explain that it was "based not upon sociological factors...[but] is a metaphysical curse rooted in the feminine personality. This is not a psychological fact; it is an existential fact." Wow.  Is this statement of Resh Lakish really an existential fact? To answer this, we need to first answer another question - what do his words actually mean?

One way to understand the aphorism is as follows:  "A widow would rather live in misery than live alone." But that's not the only translation, which depends on the exact meaning of the Aramaic phrase טן דו (tan du).  There are a number of possibilities.

Rashi

Let's start with Rashi and his explanation to our text:

בגופים שנים בעל ואשתו ואפילו אינו לה אלא לצוות בעלמא

Tan Du: Two bodies. A husband and wife; even if he is nothing more to her than company.

This explanation of Rashi's does not suggest that married misery is preferred over a single life. This is a slightly different explanation that Rashi gave in when we met this phrase in Yevamot.

טן דו - גוף שנים. משל הדיוט הוא, שהנשים אומרות טוב לשבת עם גוף שנים משבת אלמנה

Tan Du: Two bodies. This is a common maxim, for women say that it is better to live as two than to live alone.

So according to Rashi in both Yevamot and here in Kiddushin, Resh Lakish never addresses living in misery. He just made the observation that women prefer marriage over a single life.

JASTROW'S DICTIONARY

Not so Marcus Jastrow, whose dictionary (published 1886-1903) became a classic reference text for students of the Talmud. Jastrow translated טן דו as a load of grief, an unhappy married life. This will become very important later, so make note. 

THE SONCINO TRANSLATION

Moving on, the Soncino translation of Kiddushin (first published in 1966) echoes Jastrow's translation: "It is better to carry on living with trouble than to dwell in widowhood".  This is similar to the Soncino translation of the same phrase when found in Yevamot 118: "It is preferable to live in grief than to dwell in widowhood." However, a footnote to the text in Yevamot notes that "Levy compares it with the Pers., tandu, two persons." (The reference here is to Jacob Levy's  German Dictionary Chaldisches Worterbuch uber die Targumim - Aramic Dictionary of the Targums and a Large Part of Rabbinic Literature.) Why did Isidore Epstein, editor of the Soncino Talmud, choose to use Jastrow's translation over that of Levy - and that of Rashi? Answering that will take us too far off track, so we will leave it for another time... 

MELAMED'S ARAMAIC-HEBREW-ENGLISH DICTIONARY

Melamed's Aramaic-Hebrew-English Dictionary (Feldheim: Jerusalem 2005) follows Rashi : "טן דו = two bodies." 

THE ARTSCROLL TRANSLATION

The ArtScroll Schottenstein Talmud basis its translation on Rashi: "It is better to live as two together than to live alone." However a footnote (note 18) brings its meaning closer to that of Jastrow and the Soncino: "I.e it is better to be married  - even to a husband of mediocre stature - than to remain single." 

THE KOREN STEINSALTZ TRANSLATION

In his Hebrew translation of the Aramaic text found in Yevamot 118, Rabbi Steinsaltz follows Rashi, and translates  טן דו as "two bodies." A side note points out that the true origin of the phrase is not known, though it likely comes from Persian.

The newer English Koren Talmud follows the same translation: "It is better to sit as two bodies, ie., to be married, than to sit alone like as a widow. A woman prefers the any type of husband to being alone."  Elsewhere in the Koren series, (Yevamot 118a) there is a note, (written by Dr. Shai Secunda), which is more definitive than the Hebrew note. Tan Du is from middle Persian, meaning together.  It's nothing to do with being miserable.

TESHUVOT HAGE'ONIM

I've left perhaps the strongest textual witness for last: how the words Tan Du were understood during the period of the Geonim (c. 589-1038). In 1887 Avraham Harkavy published a collection of responsa from this period that he found in manuscripts held in the great library of St. Petersburg. In this collection is a reference to our mysterious words:

  טן דו בלשון פרסי שני בני אדם. ארמלו יחידות 

טן דו in Persian means two people. ארמלו means alone.

Chronologically, this is our earliest source, and, therefore, perhaps our most compelling. Case closed.

VARIATIONS OF THE RESH LAKISH RULE

So far we have the following four versions of what we will now call the Resh Lakish Rule:

It's better for a woman to be...

• ....married and unhappy than single  (Jastrow)

• ...in a less desirable or mediocre marriage than no marriage at all (ArtScroll footnote).

• ...miserable and married than to be a widow (Soncino).

• ...with a husband than to be alone (ArtScroll, Koren, Melamed, Rashi, Teshuvot Hage'onim)

WHAT IF TAN DU MEANS MISERABLE?

It seems that the translation of  טן דו as miserable originated with Jastrow, and that those who translate Resh Lakish as saying "misery is better than being single" are following in the Jastrow tradition. If we were to evaluate the Resh Lakish Rule per Jastrow (and Soncino and an ArtScroll footnote), the question is, what, precisely, constitutes  a "miserable marriage"? One in which the woman feels physically safe but emotionally alone? One in which her husband loves her dearly but is  unable to provide for her financially? Or one in which she has all the money she needs but her husband is an alcoholic? Tolstoy has taught us that each unhappy family (and presumably each miserable marriage) is unhappy in its own unique way. The point here is not to rank which is worse. 

“[In the 1950s, a] bad marriage was usually a better option for a woman, especially if she had a child, than no marriage at all.”

— Stephanie Coontz. Marriage, A History.Viking 2005. p288

Today it would be utterly silly (and incredibly rude and insulting) to suggest that a woman is better off miserable than single.  But after our review, that does not appear to be what Resh Lakish ever said.  What he really said was this: a woman would be better off (טב) married than living alone (as a widow). Resh Lakish didn't explain what he meant by better off, so we will have to assume that what he meant was a measure of overall well-being, or what we call... happiness. What we want to know, is how this understanding of Resh Lakish stands up today. Was Rabbi Soloveitchik correct when he called this "an existential fact"?

MEASURING HAPPINESS & HAPPINESS INEQUALITY

Happiness inequality exists and has been well documented. University of Pennsylvania economists Betsy Stevenson and Justin Wolfers, (who live together, but not within the bonds of marriage), note that

“...the rich are typically happier than the poor; the educated are happier than those with less education; whites are happier than blacks; those who are married are happier than those who are not; and women—at least historically—have been happier than men.”

But why is this so? Don't we all oscillate around a set point of happiness, regardless of what life may throw at us? Some psychologists think so.

LOTTERY WINNERS & ACCIDENT VICTIMS: THE SET POINT THEORY OF HAPPINESS

According to the set point theory of happiness, we all revolve around our own, innate happiness point. When we are faced with adversity, we do, to be sure, become sadder. But we eventually bounce back to where we were before, back at our set point. Similarly, when met with some good mazal, we are, for a period, more happy. But then we return to our innate set point for happiness, wherever that was prior to the good fortune. The evidence for this comes from a classic study which found that "lottery winners were not much happier than controls" and that accident victims who were paralyzed "did not appear nearly as unhappy as might have been expected." (The problem is that this study used a tiny sample - there were only 22 lottery winners and 29 paralyzed accident victims - so we need to be very cautious in generalizing from it.) 

Married people are – on average – happier than those who are single, but perhaps this fact does not suggest causation. Some would argue that it's just a correlation. A grumpy person, unable to hold down a job and miserable to be around, is not likely to find another individual willing to marry him. So it’s not that marriage makes you happier –it’s that happier people are more likely to find a partner and get married. According to this set point theory of happiness, the Resh Lakish Rule would not be supported, since the act of marrying would have no overall long-term effect on happiness.

THE MORE IS BETTER THEORY OF HAPPINESS

However, evidence from a 15 year longitudinal study of 24,000 people suggests that "marital transitions can be associated with long-lasting changes in satisfaction."  This would support the claim that marriage is causally related to happiness. It's not that you went from being a happy person who was once single to being a similarly happy person who is now married. What actually happened was that the marriage had an effect on just how happy you became.  And data from other large cohort studies show that happiness increases when people marry. Just look at the happiness of women by marital status in the figure below. Was Resh Lakish onto something?

Mean happiness of women by marital status, birth cohort of 1953-1972, from ages 18-19 and 28-29. From Easterlin, RA. Explaining Happiness. Proceedings of the National Academy of Sciences 2003. 100 (19): 11176-11183.

All this supports the Resh Lakish Rule that people are happier when they are married. (I say people because all the evidence applies equally to men too.) But we can get even more specific, because Resh Lakish used the word ארמלא, which most likely means widowed (and hence has a secondary meaning of being alone). There is actually data that applies to this more specific Resh Lakish claim about widows, and it comes from The Roper Center at the University of Connecticut. 

From Economics and Happiness, ed Bruni L. Oxford University Press 2005.

As shown in the table, 62% of women who are widowed want to be happily married.  (Of course this also means that about 40% of widowed women would rather not be married -  even happily. That’s a huge proportion. Still, the overall finding still supports the Resh Lakish Rule.) The women's perspective is the most important perspective in this conversation, and when women (widows) were asked, most wanted to be married again. Widows indeed wish to live as two rather than live alone. I don't think this amounts to anything like an existential fact, as claimed by the Rav. But the evidence from the social sciences would certainly support the Resh Lakish Rule.