CANBERRA (Reuters) - Social networking sites are the hottest attraction on the Internet, dethroning pornography and highlighting a major change in how people communicate, according to a web guru.

Bill Tancer, a self-described "data geek", has analyzed information for over 10 million web users to conclude that we are, in fact, what we click, with Internet searches giving an up-to-date view of how society and people are changing.

Some of his findings are great trivia, such as the fact that elbows, belly button lint and ceiling fans are on the list of people's top fears alongside social intimacy and rejection.

Others give an indication of people's interests or emotions, with an annual spike in searches for anti-depression drugs around Thanksgiving time in the United States.

Tancer, in his new book, "Click: What Millions of People are Doing Online and Why It Matters", said analyzing web searches did not just reflect what was happening online but gave a wider picture of society and people's behavior.

"There are some patterns to our Internet use that we tend to repeat very specifically and predictably, from diet searches, to prom dresses, to what we do around the holidays," Tancer told Reuters in a telephone interview.

Tancer, general manager of global research at Hitwise, an Internet tracking company, said one of the major shifts in Internet use in the past decade had been the fall off in interest in pornography or adult entertainment sites.

He said surfing for porn had dropped to about 10 percent of searches from 20 percent a decade ago, and the hottest Internet searches now are for social networking sites.

"As social networking traffic has increased, visits to porn sites have decreased," said Tancer, indicated that the 18-24 year old age group particularly was searching less for porn.

"My theory is that young users spend so much time on social networks that they don't have time to look at adult sites."