Cohabitation and marriage before the age of 18 represent a common pathway into adulthood in South America. Teen union formation is particularly widespread in two of the largest countries in the region, Brazil and Colombia, where long histories of organized violence related to poverty, drug trafficking operations, and civil conflict have created fertile ground for violence permissiveness and high rates of interpersonal violence.
Research examining the consequences of partnering early in life suggests that precocious exits from adolescence via teen union formation are often associated with negative outcomes that generate poverty and inequality in adulthood and perpetuate these patterns intergenerationally. One such outcome is a greater vulnerability to intimate partner violence (IPV). However, the available evidence on IPV victimization comes from settings (e.g., South Asia) where marriage markets and local conditions are considerably different from those in South America and, importantly, it is predominantly correlational in nature. While establishing associations is an essential research step, limited research disentangling causal links between early union formation and later-life outcomes, particularly troubling ones such as IPV, can lead to assumptions and stigmatizing narratives about women who enter partnerships in adolescence. These perspectives risk reinforcing ideological biases, framing early unions as inherently problematic, and resulting in ineffective or inadequate policy responses.
Establishing a clear relationship direction between teen union and IPV victimization is however more challenging than one might think because a variety of unobserved factors, such as abilities, cultural norms, and gender-related beliefs, can influence the age at which women enter partnerships and their IPV outcomes. This new study in Population and Development Review overcomes these issues by exploiting unique data from Brazil and Colombia that allow instrumenting for teen union formation with age at menarche—a factor that, in these contexts, provides a plausibly exogenous source of variation and thus allows for a more robust investigation of the relationship.
Does teen union formation affect the risk of IPV victimization later in life?
The study found consistent evidence that teen union formation increases IPV victimization in both settings. Women who entered co-residential unions before age 18 in Brazil and Colombia had higher reported rates of past-year IPV, particularly psychological violence. In Brazil, teen union formation also increased the risk of past-year sexual violence, especially among Black and Brown women in early cohabiting unions—likely reflecting vulnerabilities tied to historical biases and structural ethno-racial inequalities specific to the Brazilian society. In Colombia, women who partnered once had higher risk of lifetime sexual IPV. While these findings should be interpreted cautiously due to reporting bias, smaller sample sizes, and measurement differences across countries, observing increased risks in both recent and lifetime sexual violence speaks of the potentially persistent—and not simply mechanical—greater vulnerability to highly damaging abuse that early partnered women in these contexts may face.
Why may teen union formation lead to greater risks of IPV victimization?
While many interconnected factors—some of which are difficult to capture with purely quantitative data—may explain the link between early union formation and IPV, in Brazil and Colombia two pathways were found to be particularly important.
Detrimental impacts on schooling
In both contexts, women who entered unions before 18 were significantly less likely to complete secondary schooling, a finding supporting existing evidence that secondary education represents as a fundamental stratifier in South America. Since secondary education often coincides with early family transitions, completing it may enable women to build greater resources, human capital, and cognitive skills, which can help shield them from IPV. Given that I found no evidence of an impact of teen union on employment, in these contexts, the protective effect of education seems to stem more from the social cognition and interpersonal skills it provides rather than financial resources.
Couple age gaps
Teen union formation resulted in age-dissonant relationships, where male partners are older (5+ years). If such large age gaps represent a source of “hidden power” as many family sociologists have argued, age heterogamy (which may subsume other types of heterogamy, e.g., financial and/or educational) may reinforce status inequality within the couple. These dynamics may constrain autonomy, decision-making power and perhaps opportunities among early-partnered Colombian and Brazilian women, and then explain their greater risk of abuse, and especially of humiliation, verbal assault, and belittling.
Implications for policy
Findings from this study show that reducing adolescent marriage and other forms of early union can protect women against IPV. To the extent that they reflect causality, the results highlight the importance of increased and high-quality secondary education for women’s long-term outcomes, including in their private relationships. Given growing cross-national evidence documenting the limits of age-at-marriage laws, providing access to quality education remains a key tool in the hands of policymakers. By improving girls’ cognitive skills, opportunities outside of the domestic arena, confidence, and networks, including more frequent interactions with similarly aged peers, interventions focused on education, and secondary schooling completion in particular, would be beneficial to confront IPV in Brazil and Colombia.
Evidently, these interventions can only be planned and require long-term institutional commitments, but the prevalence of both phenomena requires immediate actions. Providing resources to recognize and exit abusive relationships for all women, not only those in early unions, and engaging men to challenge harmful norms of masculinity should be priority steps toward building societies where women and girls can thrive.