Is science really a young man's game?

It has often been remarked that science is a young man's game. Thomas Kuhn, for example, claims that revolutionary changes in science are almost always initiated by either young scientists or those new to a field. I subject Kuhn's hypothesis to testing. I examine 24 revolutionary scientific figures mentioned in The Structure of Scientific Revolutions to determine if young scientists are more likely to make revolutionary discoveries than older scientists. My analysis suggests that middle-aged scientists are responsible for initiating more scientific revolutions than young scientists, given the proportion of each group in the total population of scientists. I argue that the popular myth about the correlation between youth and scientific discovery fails to take into account the proportion of young scientists in the population of scientists.