Jon writes:
The things discussed in that program were pretty vague,...
Well first, thanks for listening to the program, I didn't expect that. It involved an investment of 15 minutes of your time.
This American Life isn't everyone's cup of tea, I hope you enjoyed it.
But second, the program wasn't at all vague when it described how the personalities displayed by the switched babies were at distinct odds with the other children of the respective families. While not scientific, it's a clear real-world example of personality traits having a heritable component.
Breast implants are pretty extreme. I don't think a general desire to attract a mate fully accounts for such drastic behaviors.
Of course genetics doesn't "fully account for" personality or behavior. The point is that personality has a heritable component, not that personality is "fully accounted for" by genetics. Your own personal experience should also tell you this is true.
--Percy