Sister
Overview

The English word sister comes from Old Norse systir which itself derives from Proto-Germanic *swestēr, both of which have the same meaning, i.e. sister. Some studies have 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, especially 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 include individuals stipulating kinship. In response, in order to avoid equivocation, some publishers prefer the usage of female sibling over sister. Males with a twin sister sometimes view her as their female alter ego, or what they would have been like if they had two X chromosomes. A study 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 and household-related errands.
length_constraints:number_paragraphs[4], oulipo:avoid_letter[o], startend:quotation