The "average" American adult reads at the eighth grade level or just below it which is also consistent with recommendations, guidelines, and norms of readability for medication directions, product information, and popular fiction. Today, American adults are being told that they have low (and declining) reading proficiency.

The reading skills of American adults are significantly lower than those of adults in most other developed countries, according to a new international survey. What’s more, over the last two decades Americans’ reading proficiency has declined across most age groups, and has only improved significantly for 65 year old adults.

The study of 160,000 people by the Organization for Economic Cooperation and Development, which is composed of two dozen developed nations, found that U.S. adults had reading levels that were below average, and lagged far behind those of Japan (which scored at the top), several Scandinavian countries, Australia and Korea. Only test takers in Spain, Italy, Ireland and several other countries hit hard by harsh economic times scored lower than Americans in U.S.

More Info: en.wikipedia.org