Activities like writing, gardening and knitting can improve your cognition and mood. Tapping, typing and scrolling? Less so.

The human hand is a marvel of nature. No other creature on Earth, not even our closest primate relatives, has hands structured quite like ours, capable of such precise grasping and manipulation.

But we’re doing less intricate hands-on work than we used to. A lot of modern life involves simple movements, such as tapping screens and pushing buttons, and some experts believe our shift away from more complex hand activities could have consequences for how we think and feel.

“When you look at the brain’s real estate — how it’s divided up, and where its resources are invested — a huge portion of it is devoted to movement, and especially to voluntary movement of the hands,” said Kelly Lambert, a professor of behavioral neuroscience at the University of Richmond in Virginia.

Dr. Lambert, who studies effort-based rewards, said that she is interested in “the connection between the effort we put into something and the reward we get from it” and that she believes working with our hands might be uniquely gratifying.