Why are women's breasts so variable in size?

I recall reading that in women estrogen is associated with a more pear shaped body -- fat accumulating on lower body, while testosterone is associated with upper body fat. Hormones play an important role in development, health and reproduction. read more

Hormones play an important role in development, health and reproduction. So since breast size is quite variable, it points to competing factors, none of which is truly decisive in all people. It is likely that the complex role of hormones and survival / reproduction led to varying body shapes depending on the environment. read more

Weight changes, medications, pregnancy and menstruation can all incite fluctuations, but breast size is largely determined by seven genetic markers [source: Erikkson et al]. Bras therefore come in an alphabet of sizes and styles because every woman inherits a unique set of breast-related DNA from her parents' genes. read more

There is an enormous range of breast sizes among women and this fact hasn’t gotten as much scientific attention as it should. This chart shows average breast volume for various bra cup sizes. read more

In a country where one in three women is overweight, you'd think there was a simple, fat-related reason for this, but obesity alone doesn't explain the jump in cup size, nor the biggest growth area in bra sales: smaller back size and bigger cup size. read more