There is certainly also considerable variation in measurement between persons. Long lasting breast growth for the duration of puberty is brought on by estrogens at the side of the growth hormone. Feminine individuals are the only mammals that completely establish breasts at puberty; all other mammals build their mammary tissue https://grok.com/share/c2hhcmQtMw%3D%3D_5ad6450c-533d-442c-a09c-9f7bce1babfb