See how Serena Williams became one of the all-time greats at the same age as Venus?
That’s what a new study shows.
“The first part is an observation,” says University of North Carolina, Chapel Hill, psychology professor Laura A. Pannucci, who was first author of the study published in the March issue of the Journal of Psychology, and is now a scientist at the National Institute of Aging, in Bethesda, Md.
The second and third parts were the result of an experimental design, in which she and her team had young and old rhesus monkeys perform a simple task.
The researchers trained the monkeys to press a spring-loaded lever (to collect their daily allotment of grapes) but also to press it when a female monkey came around to hand them grapes. Researchers then varied the female monkey’s approach speed, such that if she reached a certain point on the way around her food bowl, that time counted as a full hand.
When the female monkey was at that point, she stopped when she reached the food bowl and picked up the grapes, which were placed in a bag that was attached to her arm.
“We wanted to see how accurately the monkey would report both the female’s rate and her amount of reach,” Pannucci says. “The way they report both counts as a very impressive, interesting observation.”
For one trial of the task, an experimental monkey was given grapes and a female, and she and her new partner waited at either the beginning or the end of an experimentally manipulated distance before reaching out for grapes. They also waited at different distances before the female monkey started counting the number of grapes she’d got.
But on another trial, that same experimental monkey and a different female were given grapes and a different distance to wait before the female reached out again for the grapes. This design was meant to control for potential errors in reporting her distance from the bowl, Pannucci says.
The monkeys were placed in an open outdoor arena as they moved back and forth between the end and beginning of the distance. They spent at least two hours playing in the outdoor arena before the experiment began.
As the experimenters watched, they saw that the experimental monkey began counting the number of grapes she’d had when she reached out, even if she was at the end of the distance.
They also saw