VaYechi - Knowing your Right from your Left

RIGHT AND LEFT from the Jewish Encylopedia 1906

The right side of things is recognized in many ways as better than the left. The south and north sides of the earth are distinguished as "yamin" (right) and "sem'ol' (left; Job xxiii. 9), the right being the sunnier, brighter side, and the left the bleak and dark side, ill-omened and unlucky, where evil generates.

Bias Against Left-Handed People from wikipedia

Historically, the left side, and subsequently left-handedness, was considered negative. The word "left" itself derives from the Anglo-Saxon word lyft, "weak".^[57] In Ancient Greek both words meaning "left" were euphemisms: the word ἀριστερός, aristerós (the standard word in Modern Greek as well) is derived from ἄριστος, áristos, "best", and the word εὺώνυμος, euōnymos, "of good name", is another euphemism used in lieu of "ill-named". The Latin adjective sinister/sinistra/sinistrum originally meant "left" but took on meanings of "evil" or "unlucky" by the Classical Latin era, and this double meaning survives in European derivatives of Latin, and in the English word "sinister". Alternatively, sinister comes from the Latin word sinus meaning "pocket": a traditional Roman toga had only one pocket, located on the left side. The right hand has historically been associated with skill: the Latin word for right-handed is dexter, as in "dexterity", meaning manual skill. These words continue to be used in describing the points of an escutcheon (heraldry) where the right side of a field is refereed to as "dexter" while the left side is "sinister". Even the word "ambidexterity" reflects the bias. Its intended meaning is "skillful on both sides". However, since it keeps the Latin root dexter, which means "right", it ends up conveying the idea of being "right-handed on both sides". This bias is also apparent in the lesser-known antonym "ambisinistrous", which means "left-handed [i.e., clumsy] on both sides".^[58]...

Meanings gradually developed from use of these terms in the ancient languages. In many modern European languages, including English, the word for the direction "right" also means "correct" or "proper", and also stands for authority and justice.

Biblical Views: Left-Handed Sons of Right-Handers, Biblical Archaeology Review 39:3, May/June 2013
By Boyd Seevers and Joanna Klein

This consistent intersection of left-handedness and the tribe of Benjamin raises a question: Did this one particular tribe produce an unusually high number of left-handers? If so, why? Could it have been because of some genetic or social factor, or perhaps both? Might modern genetic studies give us some insight into this curious case of the left-handed Benjamites? Perhaps it can.

The factors that influence handedness have been studied for years, although there is still no clear understanding of all the determinants. Current research suggests that handedness is influenced by a complex interplay of both environmental and genetic factors. Studies of twins suggest that genetic effects account for 25 percent of the variation of handedness, and unique environmental influences account for the remainder. Some proposed environmental effects on handedness are societal, such as modeling handedness, forced handedness and stigmatization.

Other studies based on prenatal ultrasounds show that handedness formation occurs prenatally, before societal influences on handedness are present. Familial aggregation of handedness is also consistent with a genetic component: In one study, it was found that two left-handed parents have a 26 percent chance of having a left-handed child, while the prevalence is 20 percent with one left-handed and one right-handed parent, and 10 percent with two right-handed parents. Most recently, genetic mapping studies provide support for a genetic basis of handedness. Several genes and chromosomal locations are associated with being left-handed. It appears that there is a genetic component to handedness, but it is a very complex interaction between multiple genes that is influenced heavily by environmental factors.

Thus, it seems quite possible that the tribe of Benjamin produced more left-handed people than did other Israelite tribes. Perhaps they were genetically inclined to left-handedness, and the tribe may also have encouraged it. The Hebrew term for “left-handed” in Judges 3:15 and 20:16 literally means “restricted (’iṭṭēr) in his right hand.” Did the Benjamites bind the right arms of their sons to their sides to encourage use of the left hand? The phrase “restricted in his right hand” seems to allow for the possibility, although it may just as easily mean something like “can’t use his right hand like normal.”

Some authors suggest that Benjamites and others may have encouraged left-handedness because it would be advantageous in combat. Since soldiers would be less apt to confront a left-hander (as with Ehud), left-handed warriors may well have had an advantage in fighting hand-to-hand. In addition, ancient city gates were often built with a right-hand turn in order further to expose right-handed attackers, suggesting another possible benefit for left-handed troops.

However, the idea that left-handedness was militarily advantageous loses some of its force since the references to units of left-handed Benjamites describe slingers and archers (Judges 20:16; 1 Chronicles 12:2). Such troops used long-distance weapons, where the advantage of using the less common hand is difficult to see.

So did the tribe of Benjamin produce more left-handers, as the three Biblical passages suggest? Perhaps the Benjamites were more genetically inclined to produce left-handed people, and perhaps they also encouraged left-handedness, possibly as a mark of tribal distinction and pride.

It’s also possible that the Biblical authors merely noted left-handed Benjamites because of the irony of the handedness in the meaning of their name: Ben-jamin means “son of (my) right hand” in Hebrew, making these lefties “left-handed right-handers.”

Whatever the reason for the link of left-handers just to the tribe of Benjamin, the connection makes for a curious case, on which modern genetic studies may shed some light.

https://www.talmudology.com/jeremybrownmdgmailcom/2018/6/10/zevachim-62-to-the-right-always-to-the-right

https://www.chabad.org/library/article_cdo/aid/1097194/jewish/The-Right-and-Left-Way.htm