Robb Dunn confides a muttered aside made to him years ago by Paul Erlich:
The specific one liner I am talking about here is one I heard when Ehrlich visited North Carolina State University, where I work. I was helping to host his visit and he and I were talking at the back of a large conference room. We were both looking at the backs of a crowd of hundreds gathered in front of us and, of all things, discussing back pain. We agreed—back pain is terrible. He told me to take care of my back and then, as he looked to the audience and stepped forward through the crowd to give his talk, he left me with a sentence somewhere between punch line and universal truth…“ back problems all started when we began walking upright. The other bad thing about walking upright is that it made it hard to sniff each other…” With that, he strode, upright, to the stage and began to speak.
Sometimes, when I think of Paul Ehrlich, I think of people sniffing each other. And as several new studies reveal, when it comes to sniffing each other, men are like dogs. Women are too….
This, and much more that’s to the point of the aside, are in Dunn’s essay called “Why dogs sniff dogs, humans sniff humans, and dogs sometimes sniff humans“, for Scientific American.