If you ever happen to find yourself crossing the Capilano River in North Vancouver, Canada, youll have two bridges to choose from. The first is definitely not for the faint of heart: A mere five feet wide and 450 feet long, the Capilano Canyon Suspension Bridge is constructed solely of plank and cable and sways perilously in the wind some 250 feet above the turbulent rocky tidesright out of a scene from Alfred Hitchcocks Vertigo. Your other choice? A solidly built anchored bridge that sits a mere ten feet above sea level.
In 1974, two well-known psychologists, Arthur Aron and Donald Dutton, used these bridges as the focus of an ingenious experimentone that sought to explore the mysterious nature of sexual attraction. Its informally dubbed the Shaky Bridge Study, but I like to refer to it as the If He So Desired Test.
The two-part experiment went something like this. On day one, whenever an unaccompanied man ventured across the shaky bridge, he would find himself stopped midway by a beautiful young woman. She would introduce herself as a psychology researcher and then proceed to ask if he would mind participating in a brief survey.
On day two, the identical routine would be conducted by the same woman on the sturdy bridge.
Sounds pretty straightforward, right? But there was a little twist: When each of the men completed the survey, the young woman would hand him her phone number and tell him that he was free to call her later that evening for the resultsif he so desired.
Unbeknownst to the subjects, the real study was not the answers the men gave on the survey, but what happened afterward. Aron and Dutton set out to examine which of the men gave the pretty psychologist a call and, more importantly, why. In other words, they were interested in studying not just what happened on the bridge, but how that affected what happened later. They wanted to examine the rudiments of sexual desire, not merely the in-the-moment cause-and-reaction of talking to a pretty girl, but also how that first interaction evolved into a long-term desire for extended contact. Would the excitement and exhilaration of being on the shaky bridge, versus the more mundane experience of being on the solid bridge, promote romantic attraction?
In technical terms, Aron and Dutton were testing a concept called misattribution, also known as excitation transfer theory: Lingering excitement from one situationsay walking across a shaky bridge versus a stable onecould intensify a subsequent emotional state (in this instance, recollection of the encounter with the beautiful psychologist). Or, to put it simply: Does adrenaline make the heart grow fonder?
The answer? Indeed, it does.