This absolute is true - sisters will share clothes and shoes with each other, brothers would rather poison each other than even touch a single item of their brother's clothing let alone actually wear it.
There are so many sisters out there that love to share clothes, secrets, advice and jokes. Yet there are so many more brothers out there that the only way to show love is to gouge eyes, burn hair, bruise heavily or hamstring each other.
Why is this so? The first answer I have is that oldest primeval of conditions –competition. Each brother sees all brothers (and their mates) as the genetic competition and is ready to wipe them out at every opportunity. However each sister instinctively sees other sisters as being on the same side and uses sharing as a survival tactic. Each sister that can share resources are both benefiting and increase each others’ ability to live longer.
Lone live the sorority!