Living a long life, the conventional wisdom at the time said, depended to a great extent on who we were-that is, our genes. It depended on the decisions we made-on what we chose to eat, and how much we chose to exercise, and how effectively we were treated by the medical system. No one was used to thinking about health in terms of community.

It's as if you were interested in fashion and your neighbor when you were growing up happened to be Giorgio Armani.

I know it sounds hard to believe, but habits laid down by our ancestors persist even after the conditions that created those habits have gone away.

There are lots of issues more important than where billionaires donate their money.

I don't think people are averse to thinking about things in a deep way, but we have limited time and opportunity to think about things in a deep way. I think that's why there is an appetite for non-fiction - it gives people the opportunity to reexamine ordinary experience and be smarter about it.

For every romantic possiblity, no matter how robust, there exists at least one equal and opposite sentence, phrase, or word capable of extinguishing it.

The Tipping Point is the biography of an idea, and the idea is very simple. It is that the best way to understand the emergence of fashion trends, the ebb and flow of crime waves, or, for that matter, the transformation of unknown books into bestsellers, or the rise of teenage smoking, or the phenomena of word of mouth, or any number of the other mysterious changes that mark everyday life is to think of them as epidemics. Ideas and products and messages and behaviors spread just like viruses do.