The Science Of Childhood Bullying & Adult Mental Health - Dr Tracy Vaillancourt - #902
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Insights & moments
The myth-busts, hot takes, explainers, and tools worth keeping.
⚡Myth Buster· 6
⚡Myth Buster04:30
The Real Bully Isn't Nelson — It's the Popular Kid
Vaillancourt argues that past intervention efforts targeted the wrong archetype: the reactive, dysregulated 'Nelson' who picks on everyone and gets rejected. That kid is only about 10% of bullies. The other 90% are popular, socially skilled kids with assets the peer group values, who use aggression strategically to gain and hold power.
Roughly 10% of bullies are the dysregulated 'Nelson' type (ADHD, conduct disorder, prefrontal dysfunction)
90% are popular kids with valued assets who abuse the power those assets earn them
Popular bullies set the norms of the whole school because everyone emulates them
Old programs targeted Nelson and so missed the true bully
“that's 90% of bullies that's 90% of kids who bully others”
#bullying#popularity#power#psychology
⚡Myth Buster08:30
Bullies Often Become Successful Adults
Contrary to older studies suggesting bullies are destined for prison or misery, Vaillancourt's 16-year longitudinal cohort (followed from age 10 to 26) shows they tend to be successful. Their blend of pro-social and antisocial traits, low anxiety, and social adeptness are the same tools that pay off in adulthood — the cost is borne by society and those around them, not themselves.
16-year longitudinal cohort followed from age 10 to 26/27
Bullies tend to be successful, not incarcerated
The traits that enabled bullying (assertiveness, low anxiety, social skill) reward adults too
Main cost falls on society and their relationships, not on themselves
“we've been following kids for over 16 years... these are pretty successful individuals”
#longitudinal#outcomes#success#bullying
⚡Myth Buster13:00
Aggression Is Not Bullying — The Power Imbalance Test
A key distinction people constantly get wrong: all bullying is aggression, but not all aggression is bullying. Bullying requires a power imbalance and happens repeatedly. A one-off conflict is usually not bullying; it becomes bullying when the victim can't fight back and it recurs because of the differential in power.
All bullying is aggression; not all aggression is bullying
Bullying requires a power imbalance plus repetition
One-time incidents are typically not bullying
Conflating the two misdirects both parents and educators
“all bullying is aggressive behavior but not all aggressive behavior is bullying. Bullying happens in the context of a power imbalance”
#definition#aggression#power-imbalance#education
⚡Myth Buster13:00
The 'Bullies Come From Broken Homes' Myth
Vaillancourt knows of no study showing kids from broken homes are more likely to bully. That belief conflates general aggression (which does over-represent dysfunctional homes) with bullying, which has a distinct dark-triad profile. Blaming home life is a comforting, slightly dismissive go-to that misreads the evidence.
No study she knows of links broken homes specifically to bullying
Dysfunctional homes correlate with aggression trajectories, not bullying per se
Bullies have a distinct dark-triad profile
'Normal response to an abnormal situation' explains aggression, not bullying
“I don't know of any study off the top of my head where you see kids from broken homes more likely to bully others”
#myth#family#aggression#bullying
⚡Myth Buster29:30
Bullying Causes Weight Gain, Not the Other Way Around
A seven-year prospective study surprised Vaillancourt: the well-known link between being overweight and being bullied is driven largely by kids gaining weight as a consequence of poor treatment, not the reverse. Being bullied leads to depression, which drives overeating (or undereating), which invites more bullying — a spiral. She flags it needs replication.
Seven-year prospective study on weight and victimization
Kids gained weight after being bullied, not before
Bullying -> depression -> overeating -> more bullying spiral
First study to show it; needs replication
“they got bullied and then became bigger and then got bullied and then it just kind of spiraled”
#weight#causation#depression#longitudinal
⚡Myth Buster75:30
'Bullying Builds Resilience' — The Olympian Rebuttal
Vaillancourt rejects the claim that bullying builds character. Her thought experiment: if you won two Olympic golds and credit bullying for your drive — what if you were supposed to win 15? You can never know your unrealized ceiling, and there's a biological cost you can't see. She reframes it as the difference between succeeding because of bullying versus in spite of it.
'It made me stronger' ignores an unknowable performance ceiling
There is an invisible biological cost regardless of visible success
Reframe: 'because of that' vs 'in spite of that'
Often it's cope — meaning-making from terrible circumstances
“what if you were supposed to win 15 medals”
#resilience#myth#mindset#trauma
◆Hot Take· 2
◆Hot Take46:30
A Broken Home Is Often Just a Poor Home
Vaillancourt adds nuance to the 'keep families together' debate: when families break up, women and children are frequently left in poverty, and poverty is a huge stressor that physically changes children's brains. Much of what looks like a broken-home effect is really a poverty effect — and separating those confounds would change both the statistics and people's viewpoints.
Family breakup often leaves women and children in poverty
Poverty is a major stressor that changes children's brains
The 'broken home' effect is heavily confounded by poverty
Accounting for it statistically would change conclusions and policy
“a broken home isn't just a broken home a lot of the time it's a poor home”
#poverty#family#confound#child-development
◆Hot Take48:00
LGBT and Trans Youth: The Most Poorly Treated Group
Vaillancourt reports that lesbian, gay and bisexual students are bullied at higher rates than heterosexual peers, with context (e.g. performing-arts schools) mattering. Trans youth are particularly vulnerable, with the worst mental health she's seen in her career across a study following hundreds of thousands of Ontario kids. She notes political interference has blocked establishing whether distress precedes or follows identity, and warns against weaponizing sensational exceptions against a diverse group.
LGB students bullied at higher rates; school context modulates it
Trans youth show the worst mental-health outcomes she's seen
Temporal precedence (distress vs identity) unestablished — politics blocks the science
Sensational exceptions get weaponized against a diverse, vulnerable population
“society should be judged on how well they care for their most vulnerable and I don't think our report card's very good”
#lgbt#trans-youth#mental-health#politics
✶Explainer· 10
✶Explainer06:30
How Power Corrupts: Implicit vs Explicit Power
Vaillancourt distinguishes implicit power (earned through competencies and assets the peer group values, used without abuse) from explicit power (achieved through coercion, eliciting fear and compliance). Bullies are a blend of both — attractiveness or athletic ability gets them there first, then the power corrupts and escalates into cruelty.
Implicit power: earned via valued assets, not abused
Explicit power: coercive, elicits fear, submission and compliance
Bullies mix both — 'the beauty gets you there first and then it corrupts you'
Wielding power is good for the individual's trajectory but bad for society's
“like the beauty gets you there first and then it corrupts you and then it just escalates into you being a complete jerk”
#power#corruption#leadership#psychology
✶Explainer08:00
The Dark Triad Personality Profile of Bullies
Current research profiles bullies on the dark triad: high narcissism, high Machiavellianism, and psychopathic traits (callous, unemotional). But they are well-adjusted and socially skilled, adept at justifying their behavior to themselves and others — which is why they don't get shunned.
High on narcissism, Machiavellianism and psychopathic traits
Callous and unemotional, yet socially skilled and well-adjusted
Good at justifying bad behavior to self and others
Likely higher general intelligence and emotional intelligence — manipulation is cognitively complex
“they're really high on narcissism they're high on Machiavellianism... they have psychopathic traits”
#dark-triad#personality#narcissism#psychopathy
✶Explainer25:30
Why One School Has 15% Bullying and Another Has 70%
Across hundreds of Ontario schools, bullying rates swing from 15% to 70%. The driver is accountability: if powerful kids aren't held to account, they corrupt the environment and everyone emulates them. Victims often learn to survive by becoming aggressors themselves, spreading the behavior like a contagion that gets passed down year to year.
Observed rates range from 15% to 70% across schools
Accountability of high-status kids is the key variable
Powerful kids socialize the whole peer group toward their norms
Victims copying aggressors to survive drives contagion up to the 70s
“if you don't hold them to account they will corrupt your environment”
#school-culture#contagion#accountability#norms
✶Explainer33:00
How Girl Bullying and Boy Bullying Differ
Boys bully obviously — they value dominance and submission and tell you your flaw to your face, immediately and publicly. Girls value inclusion and exclusion and use relationships as the weapon: indirect (social/relational) aggression — rumors, exclusion, death stares, faux friendship to extract information. Girls are more proactive and instrumental; boys more reactive.
Boys: overt dominance/submission, immediate and public
Girls: indirect/relational aggression — rumors, exclusion, social freeze-out
Girls are proactive and instrumental; boys more reactive
Relational aggression appears in girls as young as three to five
“we use our relationships as a vehicle to cause harm so we're more likely to use indirect aggression”
Moral Disengagement: How Ordinary People Become Bullies
Vaillancourt calls moral disengagement the most important theory explaining how everyday people treat others cruelly and still sleep with a clear conscience. Bullies use cognitive strategies to make egregious acts palatable: dehumanizing the victim, blaming the victim, diffusing responsibility, and making advantageous comparisons ('I just called her stupid — Chris shoved her in the locker').
Moral disengagement explains how normal people bully
Strategies: dehumanize, blame the victim, diffuse responsibility, advantageous comparison
The mechanism makes cruel acts feel justified
Some interventions target moral engagement — modest but real effect
“moral disengagement I think is the most important theory that explains how everyday people become bullies”
The Cruel Paradox: Victims Hide the One Cue That Could Save Them
Bullying is usually public and humiliating, so victims suppress their distress. But distress is exactly the cue that could morally re-engage the bully or prompt bystanders, teachers and parents to intervene. In a study of 1,700 teachers, distress was the number one trigger for intervening — the very signal victims are trained by shame to hide.
Bullying is typically public; shame drives victims to hide distress
Distress is the cue that prompts bystanders and adults to step in
Study of 1,700 teachers: distress was the #1 reason they'd intervene
Suppression removes the signal the whole safety net depends on
“the one cue that maybe will get that bully to be morally engaged... is the thing that I'm suppressing”
#distress#bystanders#teachers#shame
✶Explainer61:30
A Scar That Never Heals: Bullying's Lifetime Biological Toll
Studies following people 30-50 years show you can identify someone bullied at 10 by their elevated mental-health risk at 50 and 60. Vaillancourt frames it as social pain seared into the amygdala. Chronic bullying dysregulates the HPA stress axis — cortisol first spikes, then over years down-regulates as an adaptation, changing how the person responds to every future stressor and raising later PTSD risk.
People bullied at 10 show higher mental-health risk at 50-60
Social pain is seared into the amygdala — evolutionarily, not-belonging is a survival alarm
HPA axis dysregulates: cortisol spikes early, then down-regulates over years
Blunted cortisol raises risk of PTSD from later unrelated traumas
“it's a social pain that's seared in your amygdala and you're never going to get past it”
#neurobiology#cortisol#hpa-axis#long-term-effects
✶Explainer72:00
The Healthy Context Paradox: Reducing Bullying Can Harm Remaining Victims
A counterintuitive finding replicated across Europe and now in Vaillancourt's own data: when you successfully reduce bullying, the few kids still bullied have worse mental-health outcomes. The explanation is attribution — when many are victimized, kids attribute it to 'those guys are jerks'; when you're one of the last few, you attribute it to something being fundamentally wrong with you.
Reducing bullying can leave remaining victims worse off
Replicated across Europe; confirmed in her own unpublished data
Mechanism is attribution: many victims -> 'they're jerks'; few victims -> 'something's wrong with me'
She now coaches counselors to watch for these newly-vulnerable kids
“if you reduce bullying the few kids left in the school who are bullied have worse mental outcomes”
#paradox#attribution#intervention#mental-health
✶Explainer82:00
Why Engaging Bystanders Is the Way to Kill Bullying
Since bullying is public and exists to win and hold power, it's the peer group that grants that power. Programs like Finland's KiVa (Salmivalli) and Olweus's Scandinavian model work by engaging bystanders: if the peer group rejects what a bully does, you remove the incentive. These programs succeed strongly in small countries but translate less well to the UK, Canada or the US.
Bullying is public and serves to gain/maintain power
The peer group is what awards that power — so it can withdraw it
KiVa (Finland) and Olweus (Norway) engage bystanders to remove the incentive
Strong results in small countries; weaker when scaled to larger nations
“if you could get the peer group to reject what popular bullies are doing... you've removed the incentive”
#intervention#bystanders#kiva#olweus
✶Explainer87:30
Bullying Physically Damages Memory
A 2011 Brain and Cognition study followed kids for three years and found bullying raised cortisol, which in turn impaired memory in the brain regions rich in glucocorticoid receptors — the hippocampus and prefrontal cortex. So poor academic outcomes aren't only about disengagement; bullied kids legitimately have worse verbal and episodic memory as a direct biological consequence.
2011 Brain and Cognition study, three-year prospective design
Bullying -> elevated cortisol -> impaired memory
Hits hippocampus and prefrontal cortex (high glucocorticoid receptor density)
Verbal memory suffers; part of the academic decline is biological, not just disengagement
“kids who are bullied also legitimately have poor memory as a consequence of that poor treatment”
#memory#cortisol#neurobiology#academics
❝Story· 1
❝Story40:30
'Love Withdrawal': Relational Aggression Starts in Toddlers
Vaillancourt studied 'love withdrawal' in two-year-olds — a baby version of relational aggression where a toddler refuses to kiss or hug a parent, turns their back, gives the silent treatment. Close to 80% of toddlers did this per parents and daycare teachers, evidence that humans are sophisticated social animals from the start. Williamson likens it to a golden retriever sulking when replaced by a baby cow.
'Love withdrawal' = toddler version of relational/indirect aggression
~80% of two-year-olds do it per parent and teacher reports
Suggests deep, early roots to social manipulation
First study of its kind; needs replication
“we found that close to 80% of toddlers did this as reported by parents and by their preschool teachers”
The Cheapest Anti-Bullying Fix: More Adult Supervision
Vaillancourt's passion is that schools should invest in supervision over programs. Her 2010 'places to avoid' paper mapped where bullying happens — everywhere without supervision: playgrounds, hallways, stairwells, bathrooms, the back of the bus. During the pandemic, teachers so vigilant about masks and handwashing inadvertently cut bullying 50% — the largest reduction she's seen. Even the appearance of supervision (old ladies on a bench across the street) reduced rates.
Supervision beats packaged programs and costs less
'Places to avoid' (2010): bullying clusters where there's no supervision
Pandemic vigilance inadvertently cut bullying by 50%
Even perceived surveillance (seniors on a bench) lowered rates; union rules often block hallway supervision
“guess where they get bullied Chris where there's no supervision”