Is the gene for big boobs recessive or dominant?
A trait such as breast size is far too complex and far too varied to be controlled by a single gene. On top of that, breast size also varies with hormone levels, diet, and so on. Your best indicator of breast size would be to look at other family members. If a number of them have larger breasts, then you’re probably more likely to have them as well. Again, though, there are no guarantees. Too many factors, both genetic and environmental, are at work.
