Oh, Dr. Jacob Hood, how do you manage to be such an non-nerdy nerd? In the last episode of Eleventh Hour, Hood and FBI Agents Rachel Young and Felix Lee are asked to investigate rage killings during New York Fashion Week. Hood has no idea who any of the super models are, but he is hip enough to know that they might drink appletinis. Actually, appletinis are so 2002. Maybe he is a big geek after all. Anyway, the models in question had made the tactical blunder of wearing an expensive perfume that turned out to be laced with a cocktail of pheromones and neurotransmitters. Men gathered round the runway who smelled the perfume lost all control and assaulted the models. Seems that a side effect of this particular compound is that it incites violence. Oops! But while animals definitely use chemical signals to communicate with other members of the heard, the role of pheromones in human behavior is far, far less well defined. At best, the current science indicates that pheromones have some influence on our behavior, but nothing so dramatic as mad lust. In 1971, Dr. Martha McClintock kicked off the study of pheromones when she discovered that women who live together will find themselves on the same menstrual cycle. In 1998, McClintock established a chemical basis for the syncronicity when she took fluids from the underarm of one woman and applied them to the upper lip of another woman (yuck). The second woman's menstrual cycle began to shift to match the first woman's. Since then, there's been research on a wide variety of chemical indicators between people. A 2008 study showed that when one member of a crowd becomes stressed, they emit chemical signals that increase the heart rates of nearby members of the same crowd. And in 2007, a paper in the Journal of Neuroscience said that male sweat can trigger the release of cortisol in some women, leading to feelings of stress and anxiety. But can pheromones drive you wild with uncontrollable desire? Well, let's ask the private sector, shall we? Ah yes, the Athena Institute has a nice pheromone perfume for us. And look a whole Human Pheromone Store with pheromone candles,cologne, and oil (Ew. Oil? Maybe it's to help cars love each other. Would that be autoerotic?). But really, there's little evidence that any of this stuff works. And what it won't do is drive someone into lust with you against their will. As Dr. McClintock put it in a Monitor on Psychology (published by American Psychological Association): "It's like saying that if you see a red light, you cannot control yourself from stopping no matter the circumstance," says McClintock. "Human behavior just isn't like that in any domain." Maybe Hood was right, and really we should just go back to seduction by appeltini. They worked sometimes, at least.