There is also sizeable variation in dimension in between people today. Permanent breast expansion for the duration of puberty is brought on by estrogens at the side of the growth hormone. Feminine humans are the only real mammals that forever produce breasts at puberty; all other mammals build their mammary https://grok.com/share/c2hhcmQtMw%3D%3D_5ad6450c-533d-442c-a09c-9f7bce1babfb