In 1974, Donald Dutton and Arthur Aron wanted to test the connection between sexual attraction and anxiety. They put men into two conditions. They either walked across a high, shaky bridge or a low, sturdy bridge. Afterward, they met a female experimenter who asked a series of questions and gave the men her phone number "just in case."
The men who met the woman after walking on the high bridge were more likely to call her than the men who met her on the low bridge. Psychologists call this phenomenon the "misattribution of arousal." The high bridge created a sense of arousal from the anxiety, but men mistakenly thought it was from the attraction to the woman.
That's why doing exciting things — like going for bike rides, riding a roller coaster — makes for many first dates.