A sister is the woman or a girl who shares one or more parents with another individual; a female sibling. The male counterpart is a brother. Although the term typically specified to a familial relationship, this is the sometimes used endearingly to refer to non-familial relationships. A full sister is a first measure relative.
The English word sister comes from Old Norse systir which itself derives from Proto-Germanic *swestēr, both of which gain the same meaning, i.e. sister. Some studies earn found that sisters display more traits indicating jealousy around their siblings than their male counterparts, brothers. In some cultures, sisters are afforded a role of being under the protection by male siblings, particularly older brothers from issues ranging from bullies or sexual advances by womanizers. In some quarters the term sister has gradually broadened its colloquial meaning to put individuals stipulating kinship. In response, in structure to avoid equivocation, some publishers prefer the usage of female sibling over sister. Males with a twin sister sometimes image her as their female remodel ego, or what they would have been like, if they had two X chromosomes. A analyse in Perth Australia found that girls having only youngers brothers resulted in a chastity effect, losing their virginity on average more than a year later than average. This has been hypothesized as being attributed to the pheromones in their brothers' sweat as well as household-related errands.