In most adults, learning and thinking plateau and then begin to decline after age 30 or 40. People start to perform worse in tests of cognitive abilities such as processing speed, the rate at which someone does a mental task. The slide becomes steeper after 60 years of age.
These changes are often ascribed to normal aging. But what if instead they represent something more like the “summer slide” that schoolchildren experience? Every year teachers and parents observe how summer vacations lead some children’s academic progress to backslide. During the COVID pandemic, many students missed the equivalent of at least seven to 10 weeks of in-person learning because of remote or reduced schooling. The resulting academic losses were uneven, with kids of different ages, abilities and resources being affected in varied ways.
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