In the 15th century, neo-confucianism was very rooted in the social life in the fifteenth and sixteenth centuries which lead to the strict regulation of clothing (including fabric use, colours of fabric, motifs, and ornaments) based on status. Neo-confucianism also influence women's wearing of full-pleated chima, longer jeogori, and multiple layers clothing in order to never reveal skin. The 15th century AD "chima-jeogori" style was undoubtedly a clothing style introduced from China. The women of the upper classes, the monarchy and the court wore hanbok which was inspired by the Ming dynasty clothing while simultaneously maintaining a distinctive Korean-style look; in turn, the women of the lower class generally imitated the upper class women clothing.However, by the 16th century, the jeogori had shortened to the waist and appears to have become closer fitting, although not to the extremes of the bell-shaped silhouette of the 18th and 19th centuries. In the 16th century, women's jeogori was long, wide, and covered the waist. The length of women's jeogori gradually shortened: it was approximately 65 cm in the 16th century, 55 cm in the 17th century, 45 cm in the 18th century, and 28 cm in the 19th century, with some as short as 14.5 cm. A heoritti (허리띠) or jorinmal (졸잇말) was worn to cover the breasts. The trend of wearing a short jeogori with a heoritti was started by the gisaeng and soon spread to women of the upper class. Women of lower class status were however ambivalent towards skin exposure of breasts. Among women of the common and lowborn classes, a practice emerged in which they revealed their breasts by removing a cloth to make breastfeeding more convenient. The "breast-exposing hanbok" was worn with pride as a status symbol in order to show off that they had given birth to a son and to feed her child to make other women envious; at those times, giving birth to a son was the greatest pride of a woman due to the excessive preference for male heirs in Joseon.