Last time the steepest number in the library turned out to be about friends, not adverts. In a nationally representative survey of 1,017 American boys aged 11 to 17, 17% of boys with no gambling friends had taken part in some form of gambling. Among boys whose friends mostly or all gamble, it was 84%.
What it could not say is which came first, the friends or the gambling. That is this entry's question.
Two stories that fit the same number
A boy with gambling friends could be gambling because of them. They bet in front of him, talk about it, show him the app. Or a boy already drawn to betting, or to risk in general, could have gone looking for friends like that. Researchers call the first influence and the second selection.
The survey cannot tell them apart. Every boy answered both questions at the same time, so there is no way to see which came first. And the 84% rests on 58 boys out of 1,017, a group small enough that a few answers move it a long way.
The number also gets turned around. One AI search summary reported it as "84% of boys who gamble report that their friends also gamble." The survey did not ask that. It started from the friends, not from the boys who gamble, so the summary's version is a different claim.
To separate the two stories you need to know what came first. The cleanest way is to start with people who have not gambled at all.
Start with teenagers who had never gambled
In 2018, researchers surveyed 931 students aged 12 to 17 at four high schools in Huelva, in south-west Spain. They kept the 653 who said they had never gambled, and reached 440 of them again a year later. By then 160 of the 440 had started, a little over a third.
The question was which of the things measured at the start predicted who would start. Three things about the people around them did, after accounting for sex, age, school and each other.
The more of their peers they believed gambled, the more likely they were to start: each step up a five-point scale raised the odds by about three quarters. The more they thought their peers would approve, the more likely too: each step raised the odds by about half. And the more of their friends they thought had problems with gambling, the less likely they were to start: each step cut the odds by more than half.
This is why the design matters. None of these teenagers gambled when they answered, so their own gambling cannot have chosen who they spent time with. The simplest version of "they just found each other" does not explain the result.
The last finding is the one I keep coming back to. Teenagers who thought gambling was going wrong for some of their friends were less likely to try it. The pull from peers can also be a push away.
What that study does not settle
It measured what the teenagers believed about their peers, not what their peers actually did. Each belief was a single question, and the authors name that as a limit.
The strongest predictor of all was a scale of how readily a teenager goes along with friends. Most of its questions are about vandalism, drinking, skipping school and smoking, with two reworded to gambling. That leaves room for selection. It may simply happen earlier, with teenagers who go along easily finding each other first.
What they started was mostly small. Shop scratch-cards and lottery tickets were the most common, and 81% of the new gamblers played less than once a month. This is about starting, not about harm.
The sample was half girls and the results were not split by sex, though boys were more likely to start. It was one province and four schools chosen rather than sampled at random, and the teenagers who dropped out differed from those who stayed on how much they thought their parents and peers gambled.
A second Spanish study, with a catch
The study from the last entry, which followed 1,074 students in Alicante for a year, asked how many of their friends they thought gambled. Teenagers who thought more of their friends gambled were more likely to be gambling frequently a year later, even after the other factors were accounted for.
The catch is in the authors' own words. Friends, sensation-seeking and easy access to gambling were interchangeable: any one of them could fill that place in the model, and entered together, none of them held up on its own. So the study cannot say whether it is the friends doing it, or the appetite for thrills that helps choose those friends.
What twins add
A study of 756 pairs of Minnesota twins, measured at 18 and again at 25, split the variation in gambling into what comes from genes, from the environment twins share growing up, and from everything else. At 18, the shared environment accounted for 55% and genes for 21%. By 25, the shared environment was down to 10% and genes were up to 57%. The pattern was similar in men and women.
The authors offer two readings, and they point in different directions. One is that young adults, with more independence, seek out settings that suit the tendencies they inherited, which is selection. The other is that relationships with peers may be part of what shapes gambling in those years. They tested neither, and friends were never measured. The study was funded by the National Center for Responsible Gaming, whose money comes from gambling companies and their suppliers.
Moving the belief
If beliefs about peers matter, changing them should change something. One trial did that. At a US public university, 252 students who gamble were randomly given either about five minutes of feedback comparing their gambling with what students of the same sex there actually do, or feedback on unrelated habits such as hours spent studying.
The group that got the gambling feedback lost less money, and the gap was larger at six months than at three. Their gambling problems dropped at three months, but the difference was gone by six. How often they gambled never changed. Statistically, the drop in losses was carried by the change in what they believed other students lost.
The limits: one campus, about 40% women, an average age of 23, every outcome self-reported, and no results by sex. It was also funded by the National Center for Responsible Gaming. It shows that what people believe about their peers can move how much they lose.
What young men describe
The Gambling Commission, Britain's gambling regulator, published research with 24 teenage boys and young men aged 14 to 25, carried out by Humankind Research in 2025 through four-day online diaries and hour-long interviews.
The pattern they describe is neither of the two stories above. The gambling that lasted was the gambling that reinforced friendships the boys already had: betting together, comparing results, reacting as a group. In the report's words, "often the bet itself is not the point." Solitary play, such as online casino games, lost its appeal faster. A few described the move from betting with friends to betting alone as an early warning sign.
One 23-year-old put the direction more precisely than any model: "we were definitely a bad influence on each other." Not a crowd pulling in a newcomer, and not a gambler choosing his friends, but friends who were already friends pushing each other along.
It is 24 people, so it describes rather than measures, but it was done with the people this series is about.
Young men, specifically
The one study here that followed young men over time asked a different question. In Munich, 169 men aged 18 to 25 who gamble were surveyed three times over two years, from 2014 to 2016. When a man felt more supported by the people around him, his gambling problems tended to fall at the same time.
The authors say plainly that they cannot tell which came first. After accounting for depression, anxiety, alcohol and tobacco, the link was smaller and no longer clearly significant. It measured support in general, not whether a man's friends gamble. And it was funded through the state of Bavaria, which also runs Bavaria's gambling monopoly.
I looked for a gambling study that does what this question needs: follows the same young people over time, records who becomes friends with whom and who starts gambling, and separates the two. I could not find one.
Where this leaves the question
Both stories are partly true, and they apply at different moments.
For starting, the best evidence leans toward influence. Among teenagers who had never gambled, what they believed about their peers came first, and it predicted who started.
Selection has not gone away. It may show up earlier: the teenagers who go along with friends most easily were the likeliest to start, and in the other Spanish study the appetite for thrills could stand in for friends. By 25, genes mattered more and the shared home less, which the twin researchers read partly as people choosing their own surroundings.
And once gambling is part of a friendship, the direction stops running one way. In the British research, the gambling that lasted rode on friendships that already existed, and one young man described the influence running both ways.
The part that can be acted on is the belief. What young people thought their peers did came before gambling in one study, and changing that belief cut losses in another. That is my inference from two studies, one of Spanish teenagers and one of American students, and neither split its results by sex. But it points somewhere useful: the number a young man carries in his head about how much everyone else bets.
Sources and how I checked
Every number in this entry was opened at its original source and checked against it again before the entry was written. The table lines up what AI search summaries said against what the sources actually say.
| What the search said | What the source says | How I checked |
|---|---|---|
| “84% of boys who gamble report that their friends also gamble” | Turned around. The survey found that among boys whose friends mostly or all gamble, 84% gamble themselves, against 17% of boys with no gambling friends. That 84% rests on 58 boys out of 1,017, and it is an association from one survey, not a direction. | Opened at source (full report PDF), 2026-10-26 |
| “Individual environmental factors, such as friendships, also played a role, but far less so than other factors” | Not in the study it was attributed to. The twin study never measured friendships. Its authors write that they did not directly test specific environments, and name peer relationships only as a possible influence. | Opened at source (full text (PDF copy of the published article)), 2026-10-26 |
Sources
- Common Sense Media (2026). Betting on Boys: Understanding Gambling Among Adolescent Boys
Measured on: US boys · 11-17 · USA · What I read: Opened at source (full report PDF), 2026-10-26 · Funding: Bezos Family Foundation; Jennifer Caldwell and John H.N. Fisher (underwriting named in the full report, not on the press release). Data collection by SSRS. No gambling-industry funding named. - Parrado-González, A., Fernández-Calderón, F., Newall, P.W.S. & León-Jariego, J.C. (2023). Peer and Parental Social Norms as Determinants of Gambling Initiation: A Prospective Study. Journal of Adolescent Health 73(2):296-301. doi 10.1016/j.jadohealth.2023.02.033
Measured on: Adolescents from 4 high schools in Huelva who reported no gambling at baseline; 50.9% male · 12-17 at baseline (mean 14.85) · Spain · What I read: Opened at source (full text), 2026-10-26 · Funding: Only funding statement: open-access fees paid by Universidad de Huelva/CBUA. No gambling-industry funding named. - Botella-Guijarro, A., Lloret-Irles, D., Segura-Heras, J.V., Cabrera-Perona, V. & Moriano, J.A. (2020). A Longitudinal Analysis of Gambling Predictors among Adolescents. Int. J. Environmental Research and Public Health 17(24):9266. doi 10.3390/ijerph17249266
Measured on: Same as N-115 · 13-18 at T1 · Spain · What I read: Opened at source (full text), 2026-10-26 · Funding: Not recorded on the record; ethics approval Miguel Hernandez University DPS.DLI.01.17 - King, S.M., Keyes, M., Winters, K.C., McGue, M. & Iacono, W.G. (2017). Genetic and Environmental Origins of Gambling Behaviors From Ages 18 to 25: A Longitudinal Twin Family Study. Psychology of Addictive Behaviors 31(3):367-374. doi 10.1037/adb0000266
Measured on: Minnesota Twin Family Study same-sex twin pairs born 1978-82, about 98% white; 376 male pairs, 380 female · 18 and 25 · USA · What I read: Opened at source (full text (PDF copy of the published article)), 2026-10-26 · Funding: INDUSTRY-FUNDED: National Center for Responsible Gaming (NCRG) Junior Investigator grant to the first author; data collection NIDA R37-DA005147. - Neighbors, C., Rodriguez, L.M., Rinker, D.V., Agana, M., Gonzales, R.G., Tackett, J.L. & Foster, D.W. (2015). Efficacy of personalized normative feedback as a brief intervention for college student gambling: A randomized controlled trial. Journal of Consulting and Clinical Psychology 83(3):500-511. doi 10.1037/a0039125
Measured on: US university students who gamble, SOGS 2+; 59.5% men · 18+, mean 23.1 · USA · What I read: Opened at source (full text), 2026-10-26 · Funding: INDUSTRY-FUNDED: preparation supported by the National Center for Responsible Gaming (NCRG). Conflict statement not read (truncated portion). - Gambling Commission (11 December 2025). Lived experiences of gambling in teenage boys and young men: Qualitative research
Measured on: Teenage boys and young men in Great Britain who gamble · 14-25 · Great Britain · What I read: Opened at source (web report sections (summary, research approach, methodology, findings section 4)), 2026-10-26 · Funding: Published by the GB regulator. Research agency and commissioning detail not stated in the sections read. - Bickl, A.M., Kraus, L., Loy, J.K., Kriwy, P., Sleczka, P. & Schwarzkopf, L. (2023/2024). Development of Gambling Behaviour and Its Relationship with Perceived Social Support: A Longitudinal Study of Young Adult Male Gamblers. Journal of Gambling Studies 40(1):307-332. doi 10.1007/s10899-023-10200-7
Measured on: Men in Munich who gamble (registry sample plus Facebook ads targeting gambling interests), screened in on 1+ DSM criterion, Lie/Bet or weekly gambling · 18-25 · Germany · What I read: Opened at source (full text), 2026-10-26 · Funding: OPERATOR-LINKED: Bavarian Coordination Centre for Gambling Issues, funded by the Bavarian State Ministry of Public Health; the article states the State of Bavaria runs the state gambling monopoly (lotteries, sports betting, casinos) and gave an unrestricted grant. Also Forte grant 2016-07091. Authors declare no conflicts. - National Center for Responsible Gaming (2004). NCRG Annual Report 2003
Measured on: n/a (organisational fact) · USA · What I read: Opened at source (full text (annual report) and web page), 2026-11-01 · Funding: n/a (the funder's own report) - International Center for Responsible Gaming. Our Funding (web page, accessed 2026-11-01)
Measured on: n/a (organisational fact) · USA · What I read: Opened at source (full text (annual report) and web page), 2026-11-01 · Funding: n/a (the funder's own page)
Corrections
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How this was made
This series is researched with an AI desk: it searches, reads, pulls the numbers and drafts, including this entry. I edit and decide what is published.
How I check sources · The research library
If gambling is costing you or someone close to you more than it should, the US National Problem Gambling Helpline is free and confidential: call or text 1-800-MY-RESET (1-800-697-3738), or chat at ncpgambling.org.