fraternal twin
C1Formal, Technical, Academic
Definition
Meaning
One of two siblings born from the same pregnancy but developed from two separate fertilized eggs, sharing approximately 50% of their genes, like ordinary siblings.
A term used in genetics and general discourse to describe a specific type of twin relationship, often contrasted with 'identical twin'. It can be used metaphorically to describe two things that are closely related or appear together but have distinct origins or characteristics.
Linguistics
Semantic Notes
The term is primarily biological/genetic. 'Fraternal' refers to brotherhood (from Latin 'frater'), but the term applies to male-male, female-female, and male-female twin pairs. It is synonymous with 'dizygotic twin' in technical contexts.
Dialectal Variation
British vs American Usage
Differences
No significant lexical differences. The term is standard in both varieties.
Connotations
Identical connotations in both varieties. The term is neutral and technical.
Frequency
Equally common in medical, academic, and educated general discourse in both the UK and US.
Vocabulary
Collocations
Grammar
Valency Patterns
[Subject] are fraternal twins.[Subject] and [Subject] are fraternal twins.She gave birth to fraternal twins.Vocabulary
Synonyms
Strong
Neutral
Weak
Vocabulary
Antonyms
Phrases
Idioms & Phrases
- “As different as fraternal twins (used to highlight unexpected differences between two similar things).”
Usage
Context Usage
Business
Rare. Potentially in very specific contexts like family-run businesses or inheritance discussions.
Academic
Common in genetics, biology, psychology (twin studies), and medical texts.
Everyday
Common in general conversation about families, pregnancy, and personal relationships.
Technical
Standard term in obstetrics, genetics, and demography.
Examples
By Part of Speech
verb
British English
- The twins were confirmed to fraternise from separate eggs.
- (Note: 'fraternise' is not a direct derivative; no standard verb form exists)
American English
- The study aimed to determine if they twinned fraternally or identically.
- (Note: 'twin' as a verb is rare in this context)
adverb
British English
- (No standard adverb form. Concept expressed adjectivally.)
American English
- (No standard adverb form. Concept expressed adjectivally.)
adjective
British English
- They have a fraternal twin relationship.
- The fraternal twin pair were easily distinguishable.
American English
- It was a fraternal twin birth.
- Their bond was typical of fraternal twins.
Examples
By CEFR Level
- My aunt has twins. They are fraternal twins, a boy and a girl.
- Sarah and Emma are fraternal twins, so they don't look exactly alike.
- The doctor explained that because they developed from two separate eggs, they were fraternal twins.
- Research involving fraternal twins is crucial for disentangling the effects of genetics and environment on behaviour.
Learning
Memory Aids
Mnemonic
Think 'FRATernal' as in 'fraternity' (brotherhood). They are like brothers/sisters who happened to be born at the same time, not carbon copies.
Conceptual Metaphor
TWO SEEDS, ONE POD: Emphasizes separate origins but shared environment and timing.
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Avoid direct calque 'братский близнец'. The correct Russian equivalent is 'дизиготный близнец' or 'разнояйцовый близнец'. In casual speech, 'неидентичные близнецы' (non-identical twins) is common.
Common Mistakes
- Using 'fraternal' to describe female twins only (it applies to any gender combination).
- Confusing 'fraternal' with 'paternal'.
- Misspelling as 'fraternial' or 'fraturnal'.
Practice
Quiz
What is the key biological difference between fraternal and identical twins?
FAQ
Frequently Asked Questions
Yes, fraternal twins can be male-male, female-female, or male-female, as they result from two separate eggs fertilised by two separate sperm.
Yes, these are synonymous terms. 'Fraternal' is more formal/technical, while 'non-identical' is common in everyday speech.
Yes, the tendency for a woman to release two eggs in one cycle (hyperovulation) can be hereditary, making fraternal twinning more likely in some families.
While physical differences often suggest fraternal twins, a DNA test is the only definitive way to determine zygosity (whether they are fraternal/dizygotic or identical/monozygotic).
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