We all hope to stay physically and mentally active as we grow older but the reality is often very different. Research has demonstrated that certain cognitive abilities tend to decease as we grow older, including perceptual speed and episodic memory, but this decline is hardly consistent. While some older adults develop severe memory problems at a relatively young age, even to the point of being diagnosed with dementia, others remain mentally active even into extreme old age. Though lifestyle factors including nutrition, physical exercise, and mental stimulation can help people grow older successfully, new research has also focused on the role that genetic differences can play.
Twin studies looking at genetic variability in cognitive abilities has shown that genetics plays a stronger role as we grow older, ranging from about 30% in children to well over 50% in adults. A Swedish study looking at older twins suggests that genetics can account for as much as 62% of individual differences in general cognitive ability in older adults. In recent years, researchers have identified several key genetic markers that have been linked to cognitive functioning in older adults and which can also be linked to many of the dementias that have been seen in older populations.
To read more, check out my new Psychology Today blog post.