By Melvin Durai
I’ve often wondered whether the way we treat people at different ages makes any sense scientifically. In many countries, you become an adult at age 18. That’s when you can vote, sign your name to a legally binding contract, and declare your independence from your parents (while continuing to live in their home). If you commit a serious crime at age 18, you will be put on trial as an adult, facing a lengthy prison sentence. Commit the same crime at age 17 and you may be treated as a juvenile and given a lighter punishment, a reward from the justice system for not waiting a year to misbehave. Is there really a big difference between a 17-year-old and an 18-year-old? I don’t think so.
Of course, you have to draw the line between adolescence and adulthood somewhere. But why not make it 32? After all, 32 is the age when many people get serious about finding a marriage partner and potentially moving out of their parents’ homes. You may find it ridiculous, but I have science on my side. A new study led by University of Cambridge’s MRC Cognition and Brain Sciences Unit and published in the journal Nature Communications found that there are four pivotal turning points in how the human brain develops and reconfigures over a lifetime. Neuroscientists at Cambridge compared the brains of 3,802 people from birth to age 90 to identify these turning points, which result in five major eras (or periods) of brain structure during a person’s lifetime. We begin life with a childhood brain, which lasts only until age 9 (the first turning point).
Our brain then transitions into the adolescent phase, which lasts all the way until the age of 32 (the second turning point). That’s when the adult phase begins. This is the longest era for us, continuing for more than three decades. At age 66 (the third turning point), the “early aging” phase of the brain begins. The fourth turning point occurs around age 83, when our brain shifts to the “late aging” phase. “These eras provide important context for what our brains might be best at, or more vulnerable to, at different stages of our lives,” said Dr. Alexa Mousley, a Gates Cambridge Scholar who led the research. “It could help us understand why some brains develop differently at key points in life, whether it be learning difficulties in childhood, or dementia in our later years.”
Among the four turning points, the strongest occurs around age 32, when the brain shifts from adolescence to adulthood, according to the scientists. “Around the age of 32, we see the most directional changes in wiring and the largest overall shift in trajectory, compared to all the other turning points,” Mousley said. It may come as no surprise to you, but I have very little knowledge about neuroscience. I didn’t even know that we have wires in our brains. But apparently we do –, and these wires change direction at age 32. It makes sense then, considering the scientific evidence, to change the drinking age, voting age and even marriage age to 32. I certainly don’t want any of my kids to get married before their brains are developed enough to know better than to get married. Aside from adulthood beginning at age 32, it’s also remarkable to me that it lasts until age 66. Retiring earlier than that should not be a requirement, in my view. Only when the “early aging” phase begins should anyone be compelled to retire. Some people may choose to retire sooner, but others may keep working into their 70s and 80s. As a neuroscientist might say, “Their brains are just wired differently.”
