Human life expectancy is increasing at a slower rate than it did in the 20th century, a new study of 10 wealthy countries hints.
During the 20th century, improvements in public health and medicine resulted in "radical life extension": With each passing decade, the average life expectancy at birth in some of the world's longest-lived populations in high-income countries increased by around three years. These increases in life expectancy were initially driven by reductions in the death rates of children, followed by declines in the death rates of middle-aged and older people. For instance, in the U.S. in 1900, the average life expectancy at birth was 47.3; by 2000, it had increased to 76.8.
