In the past century alone, the average human life expectancy has more than doubled. In 1900, growing up, you might expect to live 31 years. But in 2000, growing up, you might expect to live until 66 years old. Of course, this change in life expectancy varies for each country, but not as much as you might think. In general, the relatively sudden doubling of human life has been a global phenomenon. A few examples: in India, lives increased from 24 to 63 years; from 29 to 71 years in Brazil; from 35 to 70 years in Spain; from 39 to 81 in Japan; from 24 (in 1927) to 53 years in Kenya; and in the United States, from 39 to 79 years, between 1880 and 2010.
The psychological effects of such a dramatic shift in human life as this cannot and must not be taken lightly. Indeed, I would venture to say that it represents the single greatest change in the way human beings think, since, perhaps, the discovery of the New World and widespread acceptance of the idea that the Earth revolves around the sun. Just imagine yourself, for a moment, at 15 years of age, living in 1900. Your life is halfway over. You need to find a mate immediately. Maybe you have one. Maybe you or your wife is pregnant. You’re fifteen. You’re not in school anymore, are you kidding? You’re at that particular stage in life that someone, living in the year 2000, would be at when they are 30 years old – twice your age, expecting to live twice as long.
Growing up today, we are conditioned to make sacrifices for a future that is much further away in time, and much more difficult to envision, than the future for which we would have made sacrifices in 1900. Living within the law, we go to school, go to work, not necessarily enjoying either so much as enjoying the feeling of hope that the promise of future rewards generates - in short, we live to optimize our feelings about the future. But at age 15, since our respective futures are now 50 years long, instead of 15 years, we are (on average) psychologically forced to approach life with the mindset of earning an additional 35+ years worth of future rewards with which we must stuff our caves. We tolerate sedentary lifestyles, though we hate it if we are honest with ourselves, because no biped is meant to spent the overwhelming majority of their lives sitting or sleeping – tolerate i.e. dutifully agree to sacrifice no longer life for the afterlife, as in 1900, but dutifully sacrifice, today, youth for old age.
Some call this posterity. Sacrificing for posterity. But the truth is, it is posterity that we now harbor the hope, as we daydream at our desks and lie awake at night, of one day witnessing.