Brain Development Occurs in Five Distinct Eras, Study Finds
New research from cambridge University suggests the human brain doesn’t develop on a steady, continuous path, but rather progresses through five distinct eras characterized by important structural shifts. These eras begin around the ages of nine, 32, 66, and 83 years, marking key turning points in brain architecture.
The study, led by Alexa Mousley and senior authored by Professor Duncan Astle, analyzed brain institution using 12 different measures, including wiring efficiency, compartmentalization, and network connectivity. Researchers found the first phase of development spans from birth too age nine,transitioning into adolescence which lasts until approximately age 32.
Around age 32, the brainS neural wiring shifts into a prolonged adult phase lasting over three decades. A further turning point at age 66 signals the beginning of an “early ageing” phase, followed by a “late ageing” phase taking shape around age 83.
The initial childhood phase is marked by “network consolidation,” where synapses are pruned, retaining the most active connections. During this period, brain wiring efficiency decreases while gray and white matter volume rapidly increases, leading to peak cortical thickness and stabilized cortical folding.
The adolescent era (up to age 32) sees continued growth in white matter and refinement of communication networks,resulting in steadily increasing connection efficiency linked to improved cognitive performance.
The most significant shift in trajectory occurs around age 32, coinciding with a stabilization of brain architecture and, according to other studies, a plateau in intelligence and personality. Brain regions also become more compartmentalized during this phase. Researchers acknowledge that life events like parenthood may contribute to these changes, though this wasn’t directly tested in the study.
The final two eras, beginning at ages 66 and 83, are characterized by decreasing brain connectivity, believed to be associated with age-related degeneration of white matter.
Researchers emphasize that these eras represent patterns of change, not fixed states. “we’re definitely not saying that people in their late 20s are going to be acting like teenagers,” explained Mousley, “It’s really the pattern of change.” The findings may offer insights into the emergence of mental health disorders, which often appear during adolescence, and identify periods of vulnerability in brain development.
