The results are in: The nerds have won. Time to replace those arrows in the talons of the American eagle with pencils and slide rules. We’ve become the United States of Metrics.

Given our new obsessions with numbers, you’re probably eager for some statistics to back up this argument. (Actually, by this point, you’ve probably already stopped reading. A study by the Internet data company Chartbeat looked at “deep user behavior” across two billion web visits and found that 55 percent of readers spent fewer than 15 seconds on a page.)

In any event, here goes:

HEALTH Sixty-nine percent of Americans track their weight, diet or exercise, while a third track their blood pressure, sleep patterns and headaches. The market for digital fitness devices brought in $330 million last year and is expected to double this year. Samsung just added a heart-rate monitor to its popular Galaxy line of phones. The No. 1 paid app on iTunes this spring is the Sleep Cycle Alarm Clock, which monitors the amount and quality of winks you get and wakes you during a light phase of your cycle. The app is the top seller in every G-8 country.

SOCIAL MEDIA Facebook is the king of metrics. The site counts the number of friends (average 338), the number of likes on each status report, the number of comments on each report and the number of likes on each comment. Twitter, Instagram, LinkedIn, Foursquare and Tumblr all tally your followers and connections, along with the number of pass-alongs, favorites and responses. Want to know how influential you are on social media? Klout and Kred use analytics to rank your impact. Five hundred million users have calculated their Klout score on a scale from 1 to 100.

SOCIAL SCIENCE That God-shaped hole in the universe? It’s been filled with social science. Whereas once we quoted politicians or preachers, now we quote Gallup or Pew. (Actually, few neologisms better capture the change in the United States in the last 50 years than the move from pew to Pew.) There’s a study, poll or survey for everything these days. TED Talks, the headquarters of this movement, have been viewed more than a billion times, and talks are ranked by views. The hottest nonfiction book this spring is “Capital in the 21st Century,” a 696-page economic tome by Thomas Piketty.