Breasts are interesting. For starters, people interested in behavioral biology make much of the fact that in many species males have elaborated or exaggerated traits. But they seem to ignore that other than size and a bit of redistribution of muscle mass, males in humans don’t. Maybe facial hair is an elaborated trait, possibly a deeper voice, but both of these could be argued to be non-elaborated in males and, rather, altered in females. Meanwhile, human females have a whole bunch of elaborated traits. Breasts are among these traits.
There is a good explanation for this we may touch on another time. Meanwhile, I just wanted to point you to an new episode of Desiree Schell’s Skeptically Speaking in which Rachel Saunders, guest host, interviews Florence Williams, author of Breasts: A Natural and Unnatural History. Also, Scicurious weighs in on recent controversy over the relationship between human female breasts, bras, and gravity.
The episode, #215 Breasts, is here.