Centuries ago it may have been difficult for pregnant women and their children to get proper nourishment, probably leading to smaller - and therefore shorter-lived - adults.

In most, if not quite all, parts of the world, the size, shape and longevity of the human body have changed more substantially, and much more rapidly, during the past three centuries than over many previous millennia.

The rate of technological and human physiological change in the 20th century has been remarkable. Beyond that, a synergy between the improved technology and physiology is more than the simple addition of the two.

The Quest for Prosperity is an important book. Written with verve and clarity, it reflects a deep understanding of global economic issues, and proposes practical solutions that anyone concerned with the plight of the world's poor would be wise to read.

The older I get, the more important my view of the family is.

One of the most startling events in my life was when my older son was about 16, and he blamed me for all the troubles of the world. So I, I felt like telling him, Oh no, I was just like you when I was your age; I wanted to change the world, too.

In 1890, nearly everyone died on the job, and if they lived long enough not to die on the job, the average age of retirement was 85.