Ponytail

[1] In European and Western culture, it was unusual for women (as opposed to girls) to wear their hair in public in a ponytail until the mid-20th century.

Today, both women and girls commonly wear their hair in ponytails in informal and office settings or when exercising with a scrunchie or tie; they are likely to choose more elaborate styles (such as braids and those involving accessories) for formal occasions.

In Europe, in the second half of the 18th century (1751-1800), most men wore their hair long and tied back with a ribbon into what we would now describe as a ponytail,[3] although it was sometimes gathered into a silk bag rather than allowed to hang freely.

The queue lost favor amongst civilians, but continued as the mandatory hairstyle for men in all European armies until the early 19th century.

In Asia, the queue was a specifically male hairstyle worn by the Manchu people from central Manchuria and later imposed on the Han Chinese during the Qing dynasty.

[4] The queue hairstyle involves shaving the rest of the hair on the front and sides of the head, leaving a meagre portion that is tightly tied into a braid.

[5] This rule of law was upheld with the exception of monks, who attended monasteries and shaved their entire heads.

In the late 1980s, a short ponytail was seen as an impudent, edgy look for men who wanted to individualize, but keep their hair flat and functional (see mullet).

[7] Scientists in the UK have formulated a mathematical model that predicts the shape of a ponytail given the length and random curvature (or curliness) of a sample of individual hairs.

[9] The Rapunzel number is a ratio used in this equation to calculate the effects of gravity on hair relative to its length.

A long ponytail with a high Rapunzel number, hangs down, as the pull of gravity overwhelms the springiness.

[8] It is common for those who wear tight ponytails to experience traction alopecia, a form of hair loss.

[14]: 761 [15] Additionally, people who wear ponytails may experience extracranial headaches due to tension from prolonged tying of the hairs together in a bundle, pulling at the skin of the head.