A dissertation from Stockholm University examined over 10,000 Swedes born in 1953 to see what happened to children from low-income families who had at least one close friend from a more affluent background. The study used data collected in classrooms in Stockholm in the 1960s, where children themselves reported their friendships, to track participants' incomes between ages 37 and 48. The pattern was clear: children from the lowest income groups who had a friend from a more affluent family earned significantly more as adults than children who did not have such friendships. This suggests that having a friend from a more privileged background can be enough for a child from a low-income family to succeed later in life and achieve better health.
Klara Gurzo, a doctoral student at the Department of Public Health Sciences at Stockholm University, emphasized that income mobility and health are not just individual achievements or outcomes. She stated that income mobility and health are shaped by the social worlds we grow up in. According to Gurzo, these friendships can provide more than just companionship; they can expose children to other ambitions, educational paths, and networks, and indirectly provide access to resources through a friend's family.
Overall, the dissertation shows that income-related health disparities reflect both intergenerational transmission and processes that occur during a person's life. Social and historical contexts, as well as individual characteristics, shape income opportunities and health throughout life. Gurzo noted that the results suggest efforts to reduce health disparities should not only focus on socioeconomic conditions in adulthood. Instead, policy may also need to target early life environments, including school environments and peer relationships, where social capital, ambitions, and opportunities begin to take shape.
However, key unknowns remain about the generalizability of these findings to contemporary or diverse populations beyond Swedes born in 1953. Researchers have not yet determined what specific mechanisms, such as types of exposure or network access, most strongly drive the observed income benefits from cross-class friendships. Additionally, it is unclear what policy interventions, like school programs or community initiatives, would be most effective in fostering such beneficial friendships. The extent to which these friendships impact health outcomes directly versus indirectly through increased income also requires further investigation, and potential negative effects or trade-offs for children from different backgrounds in such cross-class friendships have not been fully explored.