If everybody is worried about a big correction, how come out of the money options on the S&P are cheap?

The chart shows the difference between the price of 12-month S&P options at the money, and at a strike price equal to 90% of the current price (in points of implied volatility).

Out of the money options always are more expensive, but the price differential has narrowed rather than widened of the past year. At this rate the number of German women of childbearing age will fall by two-thirds by the end of the century.