Black sheep

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A black ram

For other uses, see Black Sheep (disambiguation).

Black sheep is an English language idiom which describes an odd or disreputable member of a group, especially within one's family. The term has been looked upon either positively or negatively depending on the era and culture in which the term was used.

1 Idiomatic usage
- 1.1 Biological origin
2 Other uses
3 See also
4 References
5 External links

[edit] Idiomatic usage

Black sheep is an English language idiom—usually derogatory—which describes an odd or disreputable member of a group, especially within one's family.^[1]

The term originated from the occasional black sheep which are born into a herd of white sheep due to a genetic process of recessive traits. Black sheep were considered commercially undesirable because their wool cannot be dyed as white wool can.^[1] In 18th and 19th century England, the black color of the sheep was seen as the mark of the devil.^[2]

In modern usage, the expression has lost some of its negative connotations, and the term is usual given to the member of a group who has certain characteristics deemed inappropriate by that group.^[3]

[edit] Biological origin

In sheep, whiteness is not albinism but a dominant gene that actively switches color production off. As a result, sheep blackness is recessive, and if a white ram and a white ewe are parents of a black lamb, both must be heterozygous for black, and then there is a 25% chance that the lamb will be black. A recent study done by the Agricultural University of Norway, and The Vollum Institute of the Oregon Health Sciences University believe the black color is created by an allele E D at the extension locus.^[4]

[edit] Other uses

In psychology, the "black sheep effect" refers to the tendency of an in-group to treat or evaluate a member of its own more harshly than a similarly negative behavior or deed of an out-group member.^[5]