Anyone with siblings likely remembers a childhood spent imitating just about everything their brothers and sisters did. But according to researchers from the University of Cologne, this isn’t something you grow out of. In fact, the influence a brother or sister has on a person’s life carries on well into adulthood. Their study—which was just published in Advances in Life Course Research—analyzed data from a 32-year timeframe, and their findings led researchers to discover that people will often get married, divorced, or become a parent after seeing their sibling do it first, The Daily Mail reports.
To come to this conclusion, the team collected data from 4,521 people from the German Socio-Economic Panel Study (SOEP) that contained marital and family life information from 1984 to 2016. The biggest discovery was actually related to siblings’ influence on marriage. “An individual’s propensity to marry increases after a sibling’s marriage and remain significant in the long-term,” the researchers said. “This finding is in line with the idea that a sibling’s entry into marriage may exert pressure, especially through parents, to form a family.”
Having kids of their own also pushes a sibling to become a parent—this influence only lasting for a few years, though. “Similar to previous research, we find this effect to be short-lived, peaking in the first three years [of a child’s life] and declining afterward,” the scientists noted. And when it comes to seeing a brother or sister getting a divorce, the researchers found that other siblings will be less likely to tie the knot themselves down the road.
Zafer Buyukkececi, the lead author for the study, noted that their findings reveal that sibling relationships are a cornerstone in a family dynamic: “Taken together, our results support the idea that the process of family formation is interdependent among siblings.”