Jessica is also more irritable and depressed since losing her smell, and cries often. She feels that she has lost her quality of life, and that she's disconnected from herself and the people around her. She's also lost interest in sexual intimacy and isn't as attracted to her husband as before.

Herz explains later in the book, that we instinctively choose our mates by their smell, and having our sense of smell tampered with by external factors may cause us to choose the wrong mate. In various experiments where men and women had to choose their most preferred odor of the opposite sex, they almost always chose the odor of someone with the most different biological makeup from themselves. The exceptions are in cases where the women are on birth control pills, in which case, they choose the odor of the person with the most similar biological makeup to themselves.

Herz's theory is that for the human species to thrive, we were instinctively built, biologically, to be attracted to the mate most biologically different from ourselves, to avoid inbreeding and to ensure the survival of the species. Birth control pills mimics the conditions of pregnancy, causing us to instinctively look for safety and family, which in turn makes us attracted to mates who are more similar to us biologically, rather than mates who are biologically different from us. Herz further speculates that this may be why there is such a high divorce rate in our society. Women on birth control pills find themselves attracted to men they normally wouldn't be interested in, and after getting married and getting off the pill, they suddenly find that they are no longer attracted to their men.

It's definitely food for thought, our sense of smell controls our behaviors and actions more than we know, and it certainly explains why we have so many relationship problems. Jessica's inability to smell her husband's odor may be the reason why she finds herself losing her attraction to him.

Herz also talks about the why some odors are considered pleasant to us and unpleasant to others, and vice versa. She says that there are no universally 'good' or 'bad' odor, liking or disliking an odor is due to societal conditioning. I believe her. Living in a country where the durian is called "The King of the Fruits" and savored by locals, it astounds me that foreigners, usually Westerners, can't stand the smell of this wonderfully delicious fruit. Apparently, it works the other way around too; Westerners love cheese, which Asians supposedly can't stand. Personally, I love cheese, but I know a few friends who hate it. I suppose there may be some Westerners who love durians as well.