Teenage Brain

• Psychology
• Higher Education (degree)

Prefrontal Cortex - Pruning

Planning

Impulse Control

Rational Thinking

One of the most significant changes during adolescence is the remodelling of the prefrontal cortex,

 This process is driven by synaptic pruning, where unused neural connections are eliminated while frequently used ones are strengthened.

Implications:

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Giedd et al. (1999) used MRI scans to show that grey matter peaks in early adolescence 

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Casey et al. (2008) found that the prefrontal cortex and limbic system develop at different rates, leading to heightened emotional responses and poor impulse control.

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Blakemore  (2006)  the imbalance between cognition and emotion explains risk-taking , as teenagers rely more on the amygdala rather than the prefrontal cortex

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Structural differences  result is more impulsive and emotionally driven decision-making.

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 Yurgelun-Todd et al. (2002)  Adolescents showed stronger activation in the amygdala, whereas adults used their prefrontal cortex more, explaining why teenagers may react emotionally rather than rationally.

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Steinberg (2005) found that adolescents experience higher emotional highs and lower emotional lows than adults, which aligns with Siegel’s argument that adolescence is a time of intense emotional experience and self-discovery.

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This heightened emotional state also contributes to mood swings and risk-taking, particularly in response to peer interactions and social experiences.

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Dweck (2006) introduced the concept of growth mindset, showing that adolescents who view challenges as opportunities for growth rather than failures have greater resilience and academic success.

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Siegel recommends “mindsight” practices, which encourage teenagers to reflect on their thoughts, emotions, and behaviours, allowing them to develop self-regulation skills and reduce impulsivity.

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Tang et al. (2012) found that mindfulness meditation improves cognitive control and reduces stress, suggesting that teaching mindfulness techniques to teenagers could help them regulate emotions and make better decisions.

Solutions not problems

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Huttenlocher (2002) found that synaptic density is highest in childhood and adolescence, meaning teenagers have an enhanced ability to learn and adapt.

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Sowell et al. (2003) used MRI scans to show continued myelination into the mid-20s, indicating that processing speed and efficiency improve with age.

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Stickgold (2005), who found that REM sleep enhances problem-solving abilities and memory retention.

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 Knudsen (2004) found that adolescence is a critical period for learning, where new experiences shape neural pathways more effectively than in adulthood.

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However, Steinberg (2007) found that while adolescents are capable of logical reasoning in calm situations, their decision-making deteriorates under stress or peer pressure.

The adolescent brain is wired for rapid learning, making it ideal for skill acquisition but also vulnerable to bad habits.

The teenage brain is hypersensitive to dopamine, a neurotransmitter associated with pleasure, motivation, and reward-seeking behaviour. 

This can lead to greater risk-taking and a stronger drive for novel experiences.

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Galvan et al. (2006) conducted fMRI studies showing that the dopaminergic reward system is particularly active in adolescents, making them more likely to seek out new and exciting experiences, even if they involve potential risks.

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Casey et al. (2008) found that the imbalance between the immature prefrontal cortex and the highly active limbic system explains why adolescents engage in reckless behaviours, such as substance use, dangerous driving, and unprotected sex.

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 However, Siegel highlights that this risk-taking behaviour is not inherently negative—it fosters creativity, learning, and exploration, which are essential for identity formation and independence.

Adolescents experience a greater need for social connection, as their brains are wired to seek approval and validation from peers. This is due to increased activity in the social brain network, which strengthens relationships but can also lead to peer pressure and conformity.

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Gardner & Steinberg (2005) conducted a study where adolescents, young adults, and adults played a simulated driving game alone or with peers. The adolescents took significantly more risks when peers were present, suggesting that social influence plays a major role in risk-taking behaviour.

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Blakemore (2012) used fMRI research to show that the medial prefrontal cortex, which processes social information, is more active in teenagers, explaining their heightened sensitivity to peer evaluation.

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Siegel argues that social engagement is not just about peer pressure, but also about developing emotional intelligence, cooperation, and independence, skills that are crucial for adulthood.

The teen brain is highly susceptible to addiction, particularly to drugs, alcohol, and digital media. This is due to an overactive dopamine system, which strengthens reward-seeking behaviours.

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Volkow et al. (2003) found that adolescent brains release more dopamine in response to drugs than adult brains, making addiction more likely.

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Spear (2000) showed that adolescents are less sensitive to the sedative effects of alcohol but more sensitive to its rewarding effects, increasing the risk of binge drinking.

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Lydon et al. (2014) found that nicotine addiction is stronger in adolescents than adults, as exposure to nicotine alters the development of the dopamine system.

Teenagers need more sleep than adults due to ongoing brain development, but their circadian rhythms shift, making it harder to fall asleep early.

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Carskadon et al. (1998) found that melatonin release in teenagers occurs later in the evening, explaining why adolescents struggle to sleep early and wake up for school.

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Wheaton et al. (2016) found that later school start times improve academic performance, mood, and overall health.

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Beebe et al. (2009) linked sleep deprivation to impaired cognitive function and emotional regulation, making teenagers more prone to mood swings and poor decision-making.

Teenagers are more sensitive to stress, which can increase the risk of anxiety, depression, and mental health disorders.

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 McEwen (2007) found that chronic stress damages the hippocampus, impairing memory and increasing vulnerability to mental health disorders.

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Romeo et al. (2006) found that adolescents produce more cortisol (stress hormone) than adults, making them more reactive to stress.

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Compas et al. (2017) showed that mindfulness and cognitive-behavioural therapy (CBT) can help adolescents manage stress and anxiety.

Technology and social media significantly affect teenage brain development, particularly in attention span, mental health, and social behaviour.

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Small et al. (2009) found that internet use increases neural activity in the prefrontal cortex, but excessive screen time reduces deep-focus abilities.

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Twenge et al. (2017) linked high social media use to increased depression and anxiety in teenagers, due to constant peer comparison and cyberbullying.

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Uncapher et al. (2015) found that multitasking with digital devices reduces working memory and cognitive efficiency, meaning teenagers may struggle with deep learning and sustained attention.

There are gender differences between male and female adolescent brains, particularly in emotional processing, risk-taking, and mental health prevalence.

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Baron-Cohen (2002) found that male brains show greater systemising tendencies, while female brains show stronger empathy-related neural connections.

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Schmithorst & Holland (2006) found that girls’ brains develop language and emotional regulation areas earlier than boys, explaining differences in communication and emotional expression.

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Vermeersch et al. (2008) found that testosterone levels influence risk-taking behaviour, explaining why males are more prone to impulsivity and sensation-seeking.