They say that if the population in the top 10th percentile for IQ died, the species would revert to being hunter gatherers in 6 months,

@KiwiBird

There is a fifth dimension, beyond that which is known to man. It is a dimension as vast as space and as timeless as infinity. It is the middle ground between light and shadow, between science and superstition, and it lies between the pit of man's fears and the summit of his knowledge.