The researchers investigated how young people’s social identity affects their risk of developing problem gambling behaviour. They also investigated the influence of social support. Participants were 1,212 young people from the United States and 1,200 young people from Finland. They were 15 to 25 years old. Participants completed an online survey called YouGamble. American and Finnish participants who identified with a primary offline peer group were less likely to have problem gambling behaviour, but only if they felt supported by their peer group. Finnish participants who identified with a primary offline peer group were more likely to have problem gambling behaviour if they felt they had no social support. These results show that focusing on offline peer groups and social support may be important in preventing problem gambling among young people.