Chapter 4 Summary and Analysis

Dogs are known for their remarkable smell, but it is a little known fact that human smell is very important to humans as well. Unconsciously or not, studies prove that humans are able to tell whether a shirt has been worn by a man or woman. Smell is crucial to pleasurable sexual intercourse; one study shows that half of adults who lose their smell report lack of pleasure with sex.

However, much of this, at the level of the pheromone, remains in the realm of the subconscious in humans, where in dogs it is very much conscious. All mammals use smell in one way or another; some primates use scents to mark territory, for one example.

As a nose-opening exercise, the author suggests the reader sniff different parts of the home—plants, books, sheets—and see whether there is...