Some prior studies had suggested that face recognition might be slow to mature but fewer suspected that facial recognition might continue building for so many years into adulthood. The late-blooming nature of face recognition may simply be a case of practice making perfect.
The researchers used the web-based Cambridge Face Memory Test to test recognition of computer-generated faces among some 44,000 volunteers ages 10 to 70. They found that skill at other mental tasks, such as remembering names, maxes out at age 23 to 24, consistent with previous research, but on a face-recognition task, skill rose sharply from age 10 to 20, then continued increasing more slowly throughout the 20s, reaching a peak of 83 percent correct responses in the cohort ages 30 to 34.
"We all look at faces, and practice face-watching, all the time," says Laura T. Germine, a Ph.D. student in psychology at Harvard. "It may be that the parts of the brain we use to recognize faces require this extended period of tuning in early adulthood to help us learn and remember a wide variety of different faces."
A follow-up experiment involving computer-generated children's faces found a similar result, with the best face recognition seen among individuals in their early 30s. After this, skill in recognizing faces declined slowly, with the ability of 65-year-olds roughly matching that of 16-year-olds.
"Research on cognition has tended to focus on development, to age 20, and aging, after age 55," Germine says. "Our work shows that the 35 years in between, previously thought to be fairly static, may in fact be more dynamic than many scientists had expected."