We like to think that in days gone by, the young venerated the elderly. But that wasn’t always so. In “As You Like It,” Shakespeare’s morose character, Jaques, calls old age “second childishness and mere oblivion.” Walt Whitman hoped that the tedium and pettiness of his senior years would not infect his poetry.

Developmental psychologists, when they treated old age at all, often regarded it as a period of withdrawal. The elderly slowly separate themselves from the world. They cannot be expected to achieve new transformations. “About the age of fifty,” Freud wrote, “the elasticity of the mental processes on which treatment depends is, as a rule, lacking. Old people are no longer educable.”

Well, that was wrong. Over the past few years, researchers have found that the brain is capable of creating new connections and even new neurons all through life. While some mental processes  like working memory and the ability to quickly solve math problems  clearly deteriorate, others do not. Older people retain their ability to remember emotionally nuanced events. They are able to integrate memories from their left and right hemispheres. Their brains reorganize to help compensate for the effects of aging.

A series of longitudinal studies, begun decades ago, are producing a rosier portrait of life after retirement. These studies don’t portray old age as surrender or even serenity. They portray it as a period of development  and they’re not even talking about über-oldsters jumping out of airplanes.