As many mothers of young children are celebrated with homemade cards and sticky kisses for Mother's Day, moms of teens may be wondering why their kids just seem irritated by their presence.
"My daughter is the best eye roller in the world. I think most things I do annoy her," says Katherine Henderson, clinical psychologist in Ottawa.
She and other experts say that if this is happening in your home, it is normal and maybe even a sign of a healthy mother-child relationship. The science of teen brain development explains it too.
While it's long been known that a teen's brain is wired differently than a child's or adult's, a landmark study published last month maps out brain development across the lifespan and shows neurodevelopmental milestones for the teen years.
"It's been pretty unknown, in a quantitative way, just how big the human brain is and how it generally varies across the population," says Jakob Seidlitz, post-doctoral fellow at the Children's Hospital of Philadelphia and the University of Pennsylvania, who co-authored the study in the journal Nature.
Based on more than 120,000 MRI scans and drawn from more than 100 studies and representing more than 100,000 people from before birth to 100 years of age, researchers mapped out human brain development across a lifespan.
The study showed that the teen years are a unique point in brain development, just as they are a unique time in physical, social and emotional development. In the same way a child's weight, height and head circumference can be mapped across ages, now brain architecture can be too.
The brain begins to grow in utero, is approximately half its full size at birth and reaches its maximum size in mid-puberty. After this it gradually decreases in size over the rest of the lifespan.
As the brain grows, different structures and areas mature at different rates. The study showed that the subcortical or deep grey matter, a region with many roles including emotional control, peaks in size in mid-adolescence. Meanwhile, the amount of grey matter in the brain peaks before that, in the early school age years, and is declining by adolescence while the amount of white matter, or connections between brain cells, is continuing to increase until it peaks after 28 years.
These patterns of brain development also help to explain how teens respond to the main tasks of adolescence. Teens move from more concrete to abstract thinking and learn to problem-solve in more complex ways. They are separating form their parents and forming their own identities.
"Teens have a hard time modulating emotions," says Dr. Alene Toulany, adolescent medicine pediatrician at the Hospital for Sick Children in Toronto.
An emotional cue that "sounds like a chime to an adult, sounds like a gong to a teen...it's loud and intense. That's partly why they have a large and loud reaction," says Toulany. "They're not trying to be annoyed. They just are," she says.
"What seems often very unpredictable and intense to a parent is actually quite predictable," says Toulany. "I expect conflict among teenagers and their parents."
"That parents get less annoying to their kids over time is a beautiful description of brain development," she notes.
The challenge for parents, says Henderson, is recognizing that the behaviours mean the child needs more space to take risks, try new things, and develop their individuality.
"It's not them wanting to disconnect," says Henderson, although it may look that way on the surface. "It can be harder for parents to stay in that deep unconditional love and attuned place, but that's what teens need," she says.
"If kids show annoyance with their parents, that's usually because they feel safe to express themselves," says Henderson.
If parents can hang in through the teenage years as the brain is maturing, Henderson adds, by their 20s and 30s their values and behaviours "usually look very similar to their parents' though they might not have looked like that in adolescence."
One takeaway from the brain mapping study is that for most teens, their brains will continue to mature in a predictable way as they move into adulthood.
Henderson's advice for parents? "Hang in there...and put noise cancelling headphones on. A rolled eye is not a sign of disrespect. I actually think it shows a safety in the relationship, to be able to disagree," says Henderson.
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Michelle Ward is a pediatrician, associate professor and journalist in Ottawa. This report by The Canadian Press was first published May 7, 2022
