MIT Study Finds That Second-Born Children Are More Likely To Be Criminals

A recent study has concluded that second-born children are more likely to end up getting in trouble at school or having issues with the law later in life—a finding that is sure to bring much pleasure to older siblings everywhere.

#1

The topic of birth order on life outcomes has been extensively studied, this report claims to be the first to both quantify the relative risk and investigate the potential causes for these differing outcomes.

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Researchers from MIT, Northwestern and University of Florida (plus a few others) followed thousands of sets of brothers in Denmark and the state of Florida—two dramatically different cultures.

They found that second-born boys in both locations were more apt to run afoul of authority figures than their older peers.

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This, the researchers argue, is because their role model is a young child, rather than first-borns, whose role models are their parents. And older siblings may benefit themselves from being a role model to younger siblings, and teach them.

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"Despite large differences in environments across the two areas, we find remarkably consistent results: In families with two or more children, second-born boys are on the order of 20 to 40 percent more likely to be disciplined in school and enter the criminal justice system compared to first-born boys even when we compare siblings," the study's authors wrote.

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In a July 2017 segment on the study, NPR social science correspondent Shankar Vedantam explained the researcher’s primary hypotheses about the cause of the different outcomes:

One possible explanation has to do with the effect of parental time and investment. As many other earlier studies have noted, firstborn kids get the undivided attention of their parents, whereas kids born later are often competing for parental time and resources. Another factor that might be different is the peer group for first- and second-born kids are different. Older and younger siblings come from the same family, but they have different peer groups early in life.

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Scientists aren't sure why second-born children exhibit more behavioral problems.

The study's authors ruled out health as a factor since second-born children appear healthier. Other non-factors included schooling decisions and maternal employment.

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“These new results have important implications for social policy,” the study concluded. “Our findings that birth order appears to influence the likelihood of delinquency among boys, and that differences begin to appear early, suggests potentially fruitful avenues for monitoring and interventions.”