Hey Valentine! Love Is Literally in the Air

Sonya Schuh-Huerta

To understand the science of love (yes, science), you need to know about pheromones. They are airborne molecules that elicit a reaction, the most famous ones being potent aphrodisiacs. Pheromones are a secreted or excreted chemical factor that trigger a social response in members of the same species—in this case, humans. Ever wonder why you are attracted to someone and can’t specifically explain why? Blame it on pheromones. He or she likes your “smells” and voilá! A connection is made. Scientists have long debated whether love—or at least sexual attraction—is literally in the air. According to Sonya Schuh, assistant professor of biology, and her research and teaching in reproduction biology on, Pheromones: The Chemistry of Love Research, there is enough data in mammals including humans to substantiate the debate. Schuh is also the creative genius behind the Jan Term course The Biology of Sex, Love, and Attraction. “Students are drawn to this course because they hear the word sex, then I teach them a ton of science, and they love it,” said Schuh.

Human attraction has long been a mystery, and Schuh is passionate about her research in reproductive and developmental biology. “All of my research is in reproductive biology, various aspects of sexual reproduction and fertility and development, and how we become the individuals that we are starting from just the sperm and the egg to the early stage embryo,” said Schuh.

Schuh’s idea for the Jan Term course was born from her interest in studying reproductive biology, human physiology, sociology, and anthropology, all from a scientific lens. “What makes us uniquely human, and how we are connected to the rest of the animal kingdom, includes a number of factors. There are chemical cues and innate drives that are already in people, and it’s chemistry that draws people together,” said Schuh. “In class, I share all kinds of cool studies that have been done on animals and humans on attraction, love, human sexuality, and every aspect of human attraction.”

Schuh expressed that her Jan Term students, about half of whom are typically non-science majors, are blown away with what they learn. What they thought they already knew about sex and reproduction is completely turned upside down when they learn about the subject matter through a scientific lens. “The students love it when they learn about the external and genetic factors involved in the science of attraction. There is a lot of underlying hardwiring that helps to link us up genetically,” said Schuh.

One example is the well-known sweaty T-shirt study. Males were asked to wear a T-shirt for three days, without washing it. The shirts were then placed in individual bags and given to females to smell, who then ranked them from best smelling to worst smelling. They identified the ones that they individually preferred. Interestingly, the women preferred the dirty shirts and the stinky smells of the men who were the most genetically dissimilar to them in very specific Major Histo Compatibility (MHC) genes, which function in the immune system and fight pathogens and disease. This supports the notion that opposites attract for genetic balance, and to better ensure the chances for healthier offspring who have stronger immune systems. When the experiment was reversed and women wore the sweaty T-shirts for three days, the results were largely the same.

“When it comes to attraction and love, you are literally sniffing out the stinky sweat along with the other chemicals that are in the secretions of others,” said Schuh with a chuckle. So, when you find that special person, thank your nose for doing a good job.