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Teenagers can sometimes feel like a different species. According to neuroscientist Sarah-Jayne Blakemore, who gave this fascinating talk at TEDGlobal 2012, this isn’t a coincidence. While 15 years ago it was assumed that brain development was completed in childhood, scientists now know that the brain continues to develop through a person’s 20s and 30s. The adolescent brain is still a work in progress.

“Teenagers are often parodied, sometimes even demonized, in the media for their typical teenage behavior — they take risks, they’re moody, they’re very self-conscious,” Blakemore says in her talk. Even Shakespeare, she says, made jabs at teens. “But what’s sometimes seen as the problem of adolescence shouldn’t be stigmatized. It actually reflects changes in the brain that provide an excellent opportunity for education and social development.”

So what exactly is different between the teenage and adult brain?

For starters, the limbic system — which gives a person a rewarding feeling after taking a risk — has been found to be hypersensitive in adolescents. At the same time, MRI studies show that teenagers experience a dip in the level of gray matter in the pre-frontal cortex — the part of the brain involved in decision-making, self-awareness, planning for the future and inhibiting inappropriate behavior.

“That might sound bad, but this is a really important developmental process,” says Blakemore, the head of the Developmental Group at the UCL Institute of Cognitive Neuroscience. “The synapses that are being used are strengthened, the synapses that aren’t being used are pruned away. You can think of it a bit like pruning a rose bush … this process fine-tunes brain tissue.”

While adults are generally adept at reading gestures and facial behavior to understand what people are feeling — functioning that occurs in the medial pre-frontal cortex — this area of the brain is still developing in adolescence too. “So if you have a teenage daughter or son and think they have trouble taking other people’s perspectives — you’re right, they do,” says Blakemore.

Listening to Blakemore’s talk definitely makes my own teenage years make a lot more sense. When I was a teenager, I needed a lot of attention, which meant having bright blue hair and wearing the most outlandish things I could find — perhaps a hypersensitive limbic system at work? This got me curious — what were other TEDsters like when they were teenagers? Below, see what people had to say in this TED Conversation about the topic.

“As a teenager I thought adults were dumb and boring; I argued with my parents almost every day. I thought, ‘I’ve got the world all figured out.’ My thoughts of love were shaped by the lyrics of Westlife, The Spice Girls, Boyz II Men, Backstreet Boys and Celine Dion. I read philosophy books, wrote short stories, and loved the piano. I was sure that I would be in the film/media industry; but I had an exaggerated impression of my talent and underestimated the hard work and persistence that would be needed.” —Feyisayo Anjorio

“The world was just opening up to me. I was a nerd and athlete, and thought teachers were the greatest people. I tried to fit in with (what I thought) was the cool group. Overall, high school was great — now I like to take walks and have talks with my kids to find out who they are and where they are at in their thoughts on social issues.” —Antoinette Carvajal

“I’m only just a teenager now, but you can say I’m an obsessive computer/math nerd with rarely any need for social aspects in life.” —Patrick Quinn

“I wore the then-ubiquitous outfit of tie-dye and jeans, very long hair, bare feet, rock ‘n roll and oldies. Youth at that time embraced the comfortable and casual. My hair is shorter now but anyone would recognize me, as my current choices are not so different. There were physical risks I took then of various kinds that I would no longer take once I had children who were dependent on me to be safe and in one piece. I was wary of some but not all adults, specifically those with big and irrational tempers that seemed to consume them. I remain wary of the same sorts of people. I was independent minded both then and now.” —Fritzie Reisner

“I had no idea how brain worked — all I wanted to know was how I could influence others and their decisions to sell my stuff to them. This means I was a salesperson since I was quite young. The older I got, the more things widened up for me. I started to study Behavioural and Influential Psychology to find out more about power and flexibility of human capacity and its vulnerability.”—Edwin Nazarian

What were you like as a teenager? Chime in by adding to this ongoing TED Conversation. I’ll be adding responses to this post throughout the day.