Research shows that thinking hard pays off in later years

Researchers have found more proof that thinking hard pays handsomely in protecting brain power as you age.

In a large group of 70-year-old Scots, people who worked intellectually demanding jobs were smarter, and had better memories than those whose jobs were less cognitively demanding.

That finding held up even after researchers accounted for early differences in intelligence, education and childhood circumstances.

Among men and women whose job description entailed the regular manipulation of complex data, not only did general intelligence hold up at 70, but so did the speed at which incoming stimuli were processed.

For those whose jobs entailed complex interactions with people, general intelligence, memory and IQ were higher at 70 than for those who worked at less complex jobs. The latest findings are reported in the journal .

The existence of a large Scottish study of children born in 1936 (dubbed the Lothian birth cohort) allowed researchers to discern how much of a 70-year-old's mental function was a result of early intelligence and how much represented mental development in the work place.