Around mid-September 2007, I posted an entry on my blog about how you can do your home up with clay plaster. That the ions that clay has are the same as what humans are accustomed to when living in nature.
Since I posted this blog entry I haven't tried the clay plaster; I haven't left my studio apartment in New York. So there hasn't been a home for me to try this on.
I more recently read in the Science Times section of the New York Times that mentioned humans like being in environments that have negative ions. So you feel better with clay plaster than others because of this fact. I also realized from the New York Times article that negative ions are why I prefer to leave the windows open instead of using the air conditioner (except when it's insanely hot) and put on more clothes than use the heat. I always would get, what I called as a kid, air conditioner headaches. Maybe it was just the lack of negative ions.
Perhaps all a well-designed home needs is to make more use of what humans have evolved from, the natural world. We're all star stuff after all ;)
Here's the section of the article from "Seasonal Affective Disorder" and the link to the article from Dec 18, 2007:
"It may sound suspiciously close to snake oil, but the newest promising therapy for SAD is negative air ionization. Dr. Terman found it serendipitously when he used a negative ion generator as a placebo control for bright light, only to discover that high-flow negative ions had positive effects on mood.
Heated and air-conditioned environments are low in negative ion content. Humid places, forests and the shore are loaded with them. It makes you wonder whether there is something, after all, to those tales about the mistral and all those hot dry winds, full of bad positive ions, that supposedly drive people mad."