Though desire and its associated effects - lust, love, aggression, ambition - are generally the purview of poets, that hasn't stopped generations of thinkers from trying to explain it scientifically (and pseudoscientifically). Can desire really be described using the scientific method? Here are ten ways that researchers have answered that question with a resounding "yes."

Photo by YURALAITS ALBERT via Shuterstock.

1. Psychoanalysis: Desire is structured like a steam engine
Though many philosophers and writers addressed the nature of desire before the rise of psychoanalysis in the nineteenth century, almost none of them proposed to subject this intense human emotion to the rigors of the scientific method. Sigmund Freud and his colleagues, for all their failings, bravely set out to prove that even our feelings could be studied rationally - and this radical idea led directly to areas like neuroscience and cognitive science today. Long before fMRI machines and self-help books, Freud proposed that desire functions like the steam in an engine. If you block one exit valve, the steam will find another way out, even if it cracks the whole engine open. Freud believed that sexual repression acted as a block on exit valves, and that caused all manner of weird symptoms as people tried to unleash their desire in other ways. He believed that some of these repressed people let off steam by becoming fetishists, sexualizing objects like shoes instead of the bodies they'd been told it was naughty to desire. Other repressed people, he thought, released their desire by engaging in obsessive behaviors, developing neurotic tics, and blurting out those proverbial Freudian slips.
The upshot: you can never get rid of desire, only displace it.


2. Philosophy: Desire is structured like an emptiness
In the wake of Freud, philosophers and psychoanalysts of the twentieth century tried for even more accurate ways of describing the structure of desire. French theorist Jacques Lacan, also a psychoanalyst, spent most of his life trying to figure out how desire worked. One of his lasting contributions to the field is the idea of the petit objet a, or "little object a," (the a stands for autre or other). It's basically the ultimate, unattainable object of all our desires. It is both an abstraction, and a thing so real that to touch it would basically melt our brains (figuratively speaking). Lacan's radical idea was that everything we desire is a kind of stand-in for this little object, and so desire is a structured around a lack of something. This helps to explain a lot about how desire feels subjectively - why we keep desiring more things even after we're supposedly satisfied, and why no one person or thing or idea can ever fully complete us. The thing you want is nothing compared to that hot, impossible little object a.
The upshot: Desires can never be fully satisfied because desire is fundamentally about wanting something that doesn't exist.

3. Neuroscience: Desire is an addiction
Once scientists began studying the structure of the brain, and looking at activity in different areas, they began to gather evidence that feelings of desire occur in the brain regions that are also associated with reward and addiction. Helen Fisher, a scientist who has done fMRI studies of people who are in love, published a book called Why We Love that sums up a lot of the findings in this area. She suggests that love and its loss are functionally similar to addiction and getting sober.
The upshot: Love is a drug.


4. Neuroscience: Desire is a distributed system
Other neuroscientists have focused on the sexual side of desire, exploring what your brain is doing when you get turned on and have orgasms. One of the pioneers in this field, neuroscientist Barry Komisaruk, have mapped the brain regions that become active in women who are aroused and orgasmic. It turns out that there is no single "pleasure center" in the brain - orgasms tend to light up a wide variety of brain regions related to everything from memory to higher reason. They've also discovered that, in women at least, orgasmic impulses can reach the brain even when the spinal cord is damaged, which suggests that there are non-spinal nerve connections between the vagina and the brain.
The upshot: Sexual desire has a global effect on our nervous system.

5. Evolutionary psychology: Desire comes from the distant past
Evolutionary psychologists like Steven Pinker have popularized the idea that many human behaviors and emotions can be explained as evolutionary adaptations to a paleolithic world very different than our modern, civilized one. Our urge to punch people instead of have a rational conversation, for example, can be explained as a reflex honed 50,000 years ago, when physical struggles were the best way to survive. It's thinking like this that led to Thornhill and Palmer's now-infamous study, A Natural History of Rape, which attempted to explain rape as an evolutionary adaptation still affecting gender relations today. It's also led to countless controversial papers that claim men "naturally" have many sexual partners, while women "naturally" choose one.
The upshot: Desire is nasty, brutish, and short.

6. Pop psychology: Desire comes from conflict
Though pop psychology is hardly scientific, often its practitioners try to use the tools of psychology and evolutionary biology to prove their points. Perhaps the most famous example of this comes from the "Mars vs. Venus" school of thought, first popularized by marriage counselor John Gray in his book Men are from Mars, Women are from Venus. In it, he tries to account for why desire can be so frustrating in heterosexual relationships by claiming that women's thought patterns naturally clash with men's thought patterns. Though Gray's aim is to help Mars and Venus learn to communicate better, his basic premise is that men and women can never fully see things each other's way because they are just too different.
The upshot: Opposites attract.

7. Anthropology: What we desire places us within tribal groups
Recently there has been a growing trend among anthropologists to study sexual subcultures the same way they might study tribes or any other group with a shared set of ideas and symbols. One of the earliest studies in this area was anthropologist Gayle Rubin's essay "Thinking Sex," about how "empirical sex research" could be done on sexual minority communities - both as a way of understanding sex, but also a way of understanding how society oppresses some of its members. By examining sexual minorities' lives as if they were members of an oppressed or outcast tribe, Rubin revealed how people who desire each other sexually wind up forming communities that function like a clan might, with its own rituals, secret language, and symbols. Rubin and her colleagues have gone on to study everything from BDSM subcultures among gay men, to fetish groups, bisexuals, asexuals, transsexuals, and more.
The upshot: Desire creates community.

8. Sexology: Desire is a taxonomy of behaviors
Many anthropologists like Rubin were influenced by an earlier generation of people who set out to study sex, namely the sexologists associated with Alfred Kinsey in the early twentieth century. Kinsey, an invertebrate zoologist who studied wasps, decided to apply what he'd learned from zoology to the world of human sexuality. He'd spent most of his adult life creating elaborate spreadsheets cataloguing all the morphological quirks of thousands of wasp species. And so he used a similar technique with sexual information. He created long lists of questions to ask people about their sex lives, generating data about everything from the first time people had sex, to how many partners, what they did with them, and for how long. He published his results in two books, Sexual Behavior in the Human Male and Sexual Behavior in the Human Female, which are in many ways just giant taxonomies of human sexual behavior (as advertised). Like Rubin would be later, Kinsey was careful to document the lives of sexual outcasts like homosexuals, as well as those of married church-goers. What was ground-breaking about Kinsey's work was that he tried to be as non-judgmental as possible in his data-gathering. Unlike Freud and other students of desire before him, Kinsey didn't claim that some forms of desire were "right" and others "wrong." He treated desire as a series of acts performed by people over time - those acts didn't make the people good or bad, deviant or normal, Mars or Venus. It simply made them people engaging in behaviors, just like wasps making different kinds of nests.
The upshot: Desire is what you do, not who you are.

9. Engineering: Desire can be expressed through tool-making
In recent years, the DiY and maker movements have unleashed a new, citizen science way of exploring desire. And they're doing it by making new kinds of gadgets to enhance, elaborate, or transform sexual desire - everything from vibrators controlled by Twitter or music, to giant robots that can penetrate you while you ride a bicycle (link is NSFW). Like Kinsey, these makers view desire as an activity rather than an identity - though Rubin might argue that the maker community has its own sexual subcultures, demonstrated by the Arse Elektronika conference, and everything qdot has ever written on his blog. (Photo of the steampunk vibrator by Ani Niow.)
The upshot: Desire is what you make of it.

10. Information Science: Desire splits us into many identities
In the 1990s, MIT social scientist Sherry Turkle published a groundbreaking study called The Second Self, which was in part about how people created new identities using the internet's burgeoning social spaces. Almost two decades later, danah boyd and other information scientists developed this idea further, exploring how social networks change the way we represent ourselves and what we desire. boyd famously explained that young people use social networks to "try on" different identities, learning about what they want by taking on different selves, eventually finding the self that fits best. Lacan would probably have been fascinated by Turkle and boyd's idea that we become a series of imaginary others in order to be ourselves. Are online social networks themselves structured like desire?
The upshot: To know what you desire, you have to pretend to desire a lot of other things first.