cotwin

1 7.8

One of two children born at the same time, considered with the other child

noun
/ˈkɔːt.wɪn/

: gemelo

After years of research, scientists found that the cotwins had remarkably similar personalities, even when raised apart.
heterosexual cotwins

Examples

If respondents were interested in continuing, they were asked for permission to contact the cotwin (regardless of the twin's sexual orientation).

Academic text (2000)
In one set, the twin with the higher Klein Grid score had a lower TFRC than the cotwin with the lower Klein Grid score.

Academic text (2000)
Although all of the cotwins in the control groups were homosexual, the Klein Grid scores are usually slightly different.

Academic text (2000)
However, genes that influenced membership in the vocabulary proband group did not carry over to cotwins' PM scores.

Academic text (2013)
Homosexuals who were monozygotic (identical) twins, regardless of the sexual orientation of their cotwin, were recruited through newspaper and magazine advertisements and through the internet.

Academic text (2000)
When studying the behavior of twins, researchers often consider the environment of each cotwin in relation to the other.
In a fascinating observation, the cotwin often shares similar habits, showcasing the strong bond between twins.

Surface Forms

cotwin singular

cotwins plural

Morphology

cotwin = twin (transparent) = co + twin

Formed by productive prefix 'co-' meaning 'partner/fellow' + 'twin', so the sense 'the other/fellow twin' is directly derivable.

Etymology

Cotwin is made of co- ('with') and twin, like in coworker but for twins. So a cotwin is the other twin who is 'with' you, meaning one of the two twins often thought of together with the other twin.