Wash Your Hair Once a Week

I keep this old home-economics book, from a box of  secondhand books somebody gave us when I was a kid, because it seriously changed my life, telling me for the first time how to sit, dress, look, choose and coordinate colors and clothing styles (what?) and amazingly, said (this was 1957): "The normal scalp may be shampooed every one or two weeks. A weekly shampoo is necessary if the air is heavy with smoke and dust, or if the hair is light in color."

Shampoo every two weeks? I once went four days and my hair smelled like the camel/rhino enclosure at the zoo. What kind of world was it that this book contained? A world of either/ors, I guess:

In the culture of 50 years later, now our hair is clean but typically our posture much more resembles the dreamer/beatnik/free spirit's on the right. In fact we like her better; the controlled one is a "brownie" or "teacher's pet" or "sucking up" and certainly the boys would say she's a "high-maintenance" chick. The girl on the right -- she might let the boys get to second base, or even third.

Maybe when I was 9 and first read through this book I knew the answer to the question just above, but as an adult I understand, completely, the girl on the right.