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Susan Averett, professor and head of economics and business, was interviewed live this morning by host Matt Lauer on NBC’s “Today” show about her research that links birth order and teens’ risky behavior. The research appears in the April edition of the journal Economic Inquiry.

Excerpts from the interview follow:

ML: Susan Averett is an economics professor at Lafayette College who co-authored [a] study showing that having an older sibling can lead to risky behaviorwe’re talking about things like drinking, smoking marijuana, risky sex. Susan, is this because younger siblings are learning this from older siblings or because parents are turning the other cheek?

SA: Those are two potential explanations for the findings. We did find that parents do matter in terms of being able to reduce adolescent’s propensity to engage in these risky behaviors. But even after you look at parent supervision, the effect of the older sibling remains and it’s a pretty strong effect across various behaviors.

ML: You’re saying the effect of older siblings remains—so are you saying the younger sibling exhibits risky behavior if the older sibling has shown a pattern of that him or herself?

SA: No, that’s what’s really interesting about this. It doesn’t matter if an older sibling does this or not. We don’t have any information on the older sibling. We just know you have one. So it’s independent of whether or not the older sibling is actually engaging in these behaviors.

ML: But if you’ve got an older sibling that sets a good example who’s a straight arrow and a good student—why wouldn’t that have a positive effect on you?

SA: It may have a positive impact on you but it may also be that because you have an older sibling you’re exposed to these kinds of behaviors [earlier through] the older sibling’s peer group, or you’re watching movies at an earlier age than the older sibling.

ML: Does the behavior become riskier the number of older siblings you have? If you’ve got three older siblings, do you tend to exhibit more risky behavior?

SA: Yes. The further down you are in the birth order. Yes.

ML: For those in big families, pay attention! How does the space in age impact us? In other words, two years older than you versus seven years older?

SA: Seven years older is worse. So the further apart children are, the stronger the effect.

ML: Because they’re seeing things?

SA: I think because they’re seeing things, yes. And younger ones are being exposed to things that their older siblings didn’t get exposed to at that age. Also, maybe the parents are not supervising as closely. What’s interesting about this [study] is that a lot of stuff you read about birth order you actually find both ways. You also find older children have a harder time finding their way, or they feel that they have to be a leader and that puts a lot of pressure on them and what’s interesting about this research is that we found this effect of these risky behaviors is really remarkably consistent across several national data sets and even across cohorts. So it’s a pretty strong effect, whereas some of these other effects can go either way.

Averett’s study, “Birth Order and Risky Adolescent Behavior,” co-authored by Laura M. Argys and Daniel I. Rees, both of University of Colorado at Denver, was also featured in USA Today April 25. In addition, the Boston Globe reported on the study, and Averett has been interviewed by several radio stations.

“New research on birth order suggests that just having an older sibling can be a negative influence on younger children in the family,” reports Sharon Jayson in the USA Today article, entitled “Merely Having an Older Sibling can be Bad Influence.” The research “seeks to understand how teens get involved in risky behaviors that can have long-term economic consequences. It finds that the very existence of an older sibling increases the chances a younger sibling will drink, smoke, use marijuana or have sex.”

It is commonly believed that birth order is an important determinant of success. But previous studies in this area have failed to provide convincing evidence that birth order is related to test scores, education, or earnings.

However, according to the study, middle borns and last borns are more likely to use substances and be sexually active than their first borns.

Excerpts from the USA Today article:

“We show here that birth-order effects are quite strong,” says Susan Averett, an economics professor at Lafayette College in Easton, Pa. “We find a consistent effect. If you have an older sibling, you are more likely to engage in these risky behaviors. We don’t actually know if the older sibling is doing these things or not.”

“We hypothesized that maybe it’s just because parents get lax” after the first child, she says, but when parental supervision was added to the mix, it “didn’t mitigate the effects of the older sibling.”

Averett says parental supervision reduces the instances of these behaviors, but she says there are varying definitions of supervision. In a not-yet-published analysis of 20,000 teens, she says teens reported whether a parent is home before school, after school or at bedtime.

“There could be a big difference between being home and actively supervising your adolescent,” she says.

The published study, which was conducted through a grant from the National Institutes of Health, found that a child’s tendency toward risky behavior is influenced more by siblings than by parents.

The published study analyzed data from the National Longitudinal Survey of Youth from 1997 to 1999. It included 7,000 to 8,000 children ages 12 to 16. A second study reviewed data from 1994 to 1996 from the National Longitudinal Survey of Adolescent Health, which includes about 20,000 young people in grades seven to 12. Averett says the second study confirmed the results of the first.

A third analysis of about 6,000 high schoolers from the National Educational Longitudinal Survey in 1988, 1990 and 1992 examines the school involvement of younger siblings. It finds that although the negative influence of older siblings is clear, it’s not clear whether there are any positive effects.

The study could impact the heated debate surrounding the welfare system. Many wish to overhaul it to provide less compensation to families with more children, but Averett’s research shows that these proposals lack solid statistical support.

Averett, who often includes students in her research, has been honored with nine awards for her teaching excellence; she was the inaugural recipient of the James E. Lennertz Prize for Exceptional Teaching and Mentoring. She is coauthor of the textbook Women and the Economy: Family, Work, and Pay, is the author or coauthor of 19 journal articles, and has made 26 conference presentations. She is a member of American Economic Association, Population Association of America, and Committee on the Status of Women in the Economics Profession. She earned her doctorate in economics from University of Colorado.


Katharine Wolchik ’05 researched abstinence education and birth rates among teens as an EXCEL Scholar working with Susan Averett, professor of economics and business.

Categorized in: Academic News