Make mine a double: speaking of twins
As a twin, I spent my childhood being called the wrong name. I still turn around if I hear someone say ‘Colin’, which can be difficult to explain to people who have no idea about my not-so-secret double. Truth be told, I never found that particular mishap as annoying as “Can you read each other’s minds?” (no), “Stand back to back and see who’s taller!” (we know who’s taller; we can just tell you), and “If you were born either side of midnight, you’d be twins born on separate days!” (I don’t think we can be friends anymore). But perhaps these early moments of linguistic instability contributed to my love of aptly-used language? Whether or not that is true, musing on the matter has inspired me to delve into the language of twins, from ditokous to dizygotic and everywhere in between…
One twin, two twins, three twins, four…
The word twin is, unsurprisingly, not a recent addition to the language. Its earliest recorded use in the Oxford English Dictionary (OED) as a noun in the sense most commonly used today (i.e. plural ‘two children or young brought forth at one birth’) goes back to Old English over a millennium ago. But we twins are used to being considered as a pair rather than individuals, and this is reflected in the development of the word – the plural use predates the singular by over half a millennium, with the latter first attested around 1440, according to current research.
Twin-brother and twin-sister followed in the 17th and 18th centuries respectively, although the earliest discovered instances of both are, in fact, figurative – used to indicate a resemblance or affinity between things, rather than literal siblings. The first known use of twin-brother – ‘Heere’s the twyn-brother of thy Letter’ – appears in Shakespeare’s Merry Wives of Windsor; it is perhaps ironic that he managed to get all the way through the twin-brother-strewn Comedy of Errors without using twin-brother, although that play does provide the earliest known use of the adjective twin (in relation to siblings). This sense of the adjective is predated by two obsolete adjectives which use twin more broadly as ‘consisting of two’ (c1000) and simply ‘two; a pair of…’ (a1325).
Although the association between twin indicating ‘two’ and the number of babies considered twins is pretty obvious, in some regional dialects the word twins can be applied (as a noun) to triplets – first recorded, according to the OED’s research, in a 1606 parish register: ‘Was Baptyzed three Twines, John, Sara, and Margeret.’ More frequently, the terms used are: triplet, quadruplet (four children of one birth), quintuplet (five), sextuplet (six), septuplet (seven), octuplet (eight), and nonuplet (nine). Perhaps to the relief of expectant mothers everywhere, nine is where the OED draws a line.
Together and apart
The noun and the adjective are well-known, but of course twin can also be a verb. This can relate to birth (mothers twin their twins) or, more abstractly, to be coupled or to join. Curiously, despite usually referring to objects or people which come in a pair, the verb can also be used to mean to divide, split, or deprive of. Twin could even mean, in the 14th and 15th centuries, ‘to separate oneself from; to depart from, leave, forsake, renounce’.
This use may seem curiously alien from the happy-birthday-oh-it’s-your-birthday-too scenario, but actually developed from the concept of twins being alike objects, and thus said of one thing split in half – which demonstrates how one concept can sometimes lead to two seemingly opposing definitions of the same word.
All your eggs in one basket
One thing split in half is exactly what happens during a pregnancy which results in identical twins, of course – which is where the term monozygotic comes from: mono (one) and zygote (egg). The first question anybody asks me, when they discover I’m one of twins, is whether or not we’re identical – and they always seem faintly disappointed when I reveal that we are not. (My added assurance that ‘we look really similar’ is, quite rightly, ignored.) In future, I could simply reply that we are dizygotic – di (two) and zygote (egg), as you have probably guessed.
In 1904 it was suggested by H.H. Wilder in The American Journal of Anatomy that the terms duplicate and fraternal be used instead of identical and non-identical, and fraternal twin has certainly taken on some currency – although it feels fairly tautologous for me to refer to my fraternal twin-brother, and self-contradictory to mention a fraternal twin-sister. Non-identical may simply define us by that which we are not, but at least it avoids those pitfalls.
And then, of course, there are conjoined twins: twins born physically joined together in some manner. Various terms for conjoined twins indicate the part of the anatomy which is the site of attachment, alongside the suffix –pagus (from the ancient Greek πάγος meaning that which is fixed) – hence craniopagus (conjoined twins attached at the head), thoracopagus (those attached at the thorax), pygopagus (those attached at the buttocks) etc. The term Siamese twins popularly used to refer to conjoined twins (and now often considered inappropriate or offensive), derives from a specific pair of conjoined twins from Siam named Chang and Eng Bunker (1811-1874), who became naturalized U.S. citizens.
And what of you non-twins? Don’t worry, you have your own word too. The term singleton was popularized in the 1990s by Bridget Jones’s Diary, where the hapless heroine often used the word as a lament of her unmarried state. That use – which falls under the broader definition ‘one who is alone or unaccompanied’ – is currently dated to 1937, but is preceded by other senses, including one originating in 1931 which is more relevant to this article. Any child who is not a twin, triplet, or other multiple birth is a singleton. So, sorry Bridget, I hate to break it to you: you were a singleton twice over.
A twin by any other name
As I scrolled through the entries of the OED website, using the advanced search to see which entries had ‘twins’ mentioned in their definitions, I stumbled across some interesting words that even I – a twin for all but the first nine minutes of my life – had never heard of. Did you know that gemels is an obsolete word for twin (relating to the Old French gemel, and thus with similarities to the modern French jumeau)? Were you aware that a pair of male and female twins can be termed a pigeon pair? And would you know to describe an animal which has had twins as ditokous? You could equally call her a twinner, and (perhaps my favourite) certain dialects would describe a mother as having twindled – and the twins could themselves be called twindles.
Now I, for one brief period, was known at school as Twinny’s Twin (guess who was Twinny?) but nobody, so far as I’m aware, has ever called me a twindle. Dear everyone I know – please start.