Some women naturally have a smaller chest, while others have larger breasts. Both are completely normal. Breast size can also change throughout a person’s life because of hormonal fluctuations, weight changes, pregnancy, breastfeeding, medications, and aging.
Just as people inherit differences in height, facial features, hair texture, and body proportions, they can inherit different patterns of breast development.
This means there is no universal relationship between breast size and other parts of the body.
A woman with small breasts can have any range of normal anatomy elsewhere, just as a woman with larger breasts can.
One reason these myths survive is that people sometimes assume the entire body develops according to one simple pattern.
Breast tissue responds strongly to hormones such as estrogen and progesterone. Genetics and body-fat distribution also contribute to breast size and shape.
Genital anatomy, meanwhile, develops through its own biological processes and varies naturally among individuals.
There is no scientific rule stating that a particular breast size corresponds to a particular genital size or shape.
In other words, looking at someone’s chest cannot provide a reliable measurement or prediction of their intimate anatomy.