1. Study suggests having a parent with an alcohol use disorder increases risk for teenage dating violence

    October 18, 2017 by Ashley

    From the University at Buffalo press release:

    Having a parent with an alcohol use disorder increases the risk for dating violence among teenagers, according to a study from the University at Buffalo Research Institute on Addictions.

    In addition, researchers found that the root causes of teen dating violence can be seen as early as infancy.

    “Although teen dating violence is typically viewed as a problem related specifically to adolescent development, our findings indicate that the risk for aggressive behavior and involvement in dating violence are related to stressors experienced much earlier in life,” says Jennifer A. Livingston, PhD, senior research scientist at RIA and lead author of the study.

    Livingston evaluated 144 teenagers who had fathers with an alcohol use disorder and who had been initially recruited for study at 12 months of age. By analyzing data that was collected regularly over the course of their lifespan, Livingston was able to identify factors that led to some of the teenagers to be involved in abusive dating relationships.

    “It appears that family dynamics occurring in the preschool years and in middle childhood are critical in the development of aggression and dating violence in the teenage years,” she says.

    Mothers living with partners who have alcohol use disorder tended to be more depressed and, as a result, were less warm and sensitive in their interactions with their children, beginning in infancy. “This is significant because children with warm and sensitive mothers are better able to regulate their emotions and behavior,” Livingston says. “In addition, there is more marital conflict when there is alcohol addiction.”

    These conditions can interfere with children’s abilities to control their own behavior, resulting in higher levels of aggression in early and middle childhood. Children who are more aggressive in childhood, particularly with their siblings, are more likely to be aggressive with their romantic partners during their teen years.

    “Our findings underscore the critical need for early intervention and prevention with families who are at-risk due to alcohol problems. Mothers with alcoholic partners are especially in need of support,” Livingston says. “Our research suggests the risk for violence can be lessened when parents are able to be more warm and sensitive in their interactions with their children during the toddler years. This in turn can reduce marital conflict and increase the children’s self-control, and ultimately reduce involvement in aggressive behavior.”


  2. Study examines sleep problems in young people

    October 16, 2017 by Ashley

    From the James Cook University press release:

    A collaborative research project involving James Cook University and the University of Queensland indicates high rates of sleep problems continuing through teenage years and into early adulthood — but also suggests a natural remedy.

    Dr. Yaqoot Fatima from JCU’s Mount Isa Centre for Rural and Remote Health was associated with a study that tracked more than 3600 people from the age of 14 until they were 21.

    “Just over a quarter of the 14-year-olds reported sleep problems, with more than 40 percent of those still having sleep problems at 21,” said Dr. Fatima.

    She said the causes of sleep problems were different at different ages.

    Maternal factors, such as drug abuse, smoking, depression and anxiety among mothers are the most significant predictors of adolescent sleep problems in their children, at 14-years-old. For all people studied, being female, having experienced early puberty, and being a smoker were the most significant predictors of sleep problems at 21 years.”

    She said adolescent depression or anxiety were linking factors for sleep problems between the two ages.

    “It’s a vicious circle. Depression and anxiety are well-established risk factors for sleep problems and people with sleep problems are often anxious or depressed,” she said.

    Dr. Fatima said that as well as the traditional factors, excessive use of electronic media is emerging as another significant risk.

    “In children and adolescents, it’s found to be strongly associated with later bedtime and shorter sleep duration, increasing the risk of developing sleep disturbances,” she said.

    Dr. Fatima said the study was worrying as it revealed a high incidence of persistent sleep problems and possible concurrent health problems among young people — but it also strongly suggested an answer to the problem.

    “Even allowing for Body Mass Index and other lifestyle factors, we found that an active lifestyle can decrease future incidence and progression of sleep problems in young subjects. So, early exercise intervention with adolescents might provide a good opportunity to prevent their sleep problems persisting into later life.”

    She said the next study being considered would look at what factors lead to young adults’ sleep problems continuing as they grow older and how that might be prevented.


  3. Study suggests anxiety and depression caused by childhood bullying decline over time

    by Ashley

    From the University College London press release:

    A new UCL-led study has provided the strongest evidence to date that exposure to bullying causes mental health issues such as anxiety years later.

    The study, published today in JAMA Psychiatry and funded by MQ: Transforming Mental Health and the Economic and Social Research Council, found that the detrimental effects of bullying decreased over time, which the authors say shows the potential for resilience in children exposed to bullying.

    “Previous studies have shown that bullied children are more likely to suffer mental health issues, but give little evidence of a causal link, as pre-existing vulnerabilities can make children both more likely to be bullied and experience worse mental health outcomes. We used a robust study design to identify causation,” said the study’s lead author, Dr Jean-Baptiste Pingault (UCL Psychology & Language Sciences).

    The study involved 11,108 participants from the Twins Early Development Study (TEDS), which is based at King’s College London. By surveying twins, researchers were able to look at the associations between bullying and mental health outcomes, and then account for the confounding effects of their genes and shared environmental influences because they studied both monozygotic (“identical”) twins who have matching genes and home environments and dizygotic (“non-identical”) twins, who don’t share all of their genes, but have matching home environments. Both children and their parents filled out questionnaire: at age 11 and 14 they were asked about peer victimization, and at 11 and 16 they were asked about mental health difficulties.

    The effect sizes were stronger before controlling for shared environmental factors and genetics, confirming that bullying itself is only partly to blame for the poor mental health outcomes experienced by bullied children.

    The researchers found that, once confounding factors were removed, there remained a causal contribution of exposure to bullying to concurrent anxiety, depression, hyperactivity and impulsivity, inattention, and conduct problems. Two years later, the impact on anxiety persisted. Five years later, there was no longer an effect on any of those outcomes, but 16-year-olds who had been bullied at age 11 remained more likely to have paranoid thoughts or cognitive disorganisation (a tendency for thoughts to become derailed).

    “While our findings show that being bullied leads to detrimental mental health outcomes, they also offer a message of hope by highlighting the potential for resilience. Bullying certainly causes suffering, but the impact on mental health decreases over time, so children are able to recover in the medium term,” Dr Pingault said.

    “The detrimental effects of bullying show that more needs to be done to help children who are bullied. In addition to interventions aimed at stopping bullying from happening, we should also support children who have been bullied by supporting resilience processes on their path to recovery. Our findings highlight the importance of continuous support to mental health care for children and adolescents” he said.

    Dr Sophie Dix, Director of Research at MQ: Transforming Mental Health said: “This important research is further strong evidence of the need to take the mental health impacts of bullying seriously. We hope this study provides fresh impetus to make sure young people at risk — and those currently being bullied — get effective help as soon as possible.”

    “More than one in five UK young people say they’ve recently been bullied. And now this unprecedented study gives the strongest evidence to date that bullying can directly cause many common mental health conditions — and have a serious effect on mental health in the long-term. But the good news is that it shows that people can and do get better — demonstrating the importance of resilience. Now we need to understand why this is and develop new ways, through research, to intervene and change lives,” she said.


  4. Study debunks claim of “narcissism epidemic” among college students

    October 15, 2017 by Ashley

    From the University of Illinois at Urbana-Champaign press release:

    Today’s college students are slightly less narcissistic than their counterparts were in the 1990s, researchers report in a new study — not significantly more, as some have proposed.

    The study, reported in the journal Psychological Science, analyzed data from 1,166 students at the University of California, Berkeley in the 1990s, and from tens of thousands of students at the University of Illinois at Urbana-Champaign and the University of California, Davis in the 2000s and 2010s. All of the students completed the Narcissism Personal Inventory, the oldest and most widely used measure of narcissism.

    According to some researchers and observers, recent generations of young people are suffering through an ‘epidemic of narcissism’ characterized by an exaggerated sense of their own gifts and accomplishments and by the expectation that others recognize their greatness. The rise in narcissism is believed to be the result of permissive parenting, unregulated access to the internet and an overuse of social media platforms that reward self-aggrandizement, said University of Illinois psychology professor Brent Roberts, who led the new analysis.

    But there is no compelling evidence that recent generations are more narcissistic than previous ones, he said.

    The Narcissism Personality Inventory is designed to measure an individual’s narcissistic tendencies. Each of its 40 questions asks participants to choose between two statements that define their attitudes and beliefs. One of each pair of answers is more consistent with a narcissistic outlook. For example:

    • I just want to be reasonably happy.
    • I want to amount to something in the eyes of the world.

    AND

    • I insist on getting the respect that is due me.
    • I usually get the respect that I deserve.

    Roberts and his colleagues first focused on whether the NPI reliably measured the same traits over time and among different constituencies.

    “For the most part, the measure worked pretty well, but we found a few items that didn’t work consistently across different groups,” Roberts said. “When you adjust for that, you see decreases in narcissism from the 1990s to the 2000s to the 2010s.”

    The team next looked at specific aspects of narcissism, such as leadership, vanity and entitlement, and saw a similar downward trend in each of these traits between 1992 and 2015. The declines were small but significant, and occurred gradually over time. Males and females, Asians, African-Americans and Caucasians all saw decreases in narcissism, but to differing degrees, Roberts said.

    “The average college student scores 15 to 16 on the NPI scale, out of a possible 40,” Roberts said. “The average grandparent scores about 12. Based on that, if you use that as a natural metric, most people are not narcissists. And, perhaps most interestingly, narcissism declines with age.”

    Roberts and his colleagues believe that older adults like the idea of a narcissism epidemic among the young because young people tend to be more narcissistic than they are.

    “We have faulty memories, so we don’t remember that we were rather self-centered when we were that age,” Roberts said.

    The denigration of millennials and even younger generations paints them as lacking in values or as having bad personality characteristics, he said.

    “But that’s just wrong,” he said. “The kids are all right. There never was a narcissism epidemic, despite what has been claimed.”


  5. Study suggests earlier school start times may increase risk of adolescent depression and anxiety

    October 13, 2017 by Ashley

    From the University of Rochester Medical Center press release:

    Teenagers who start high school before 8:30 a.m. are at higher risk of depression and anxiety, even if they’re doing everything else right to get a good night’s sleep, a recent study out of Rochester, N.Y., suggests.

    Led by University of Rochester Medical Center clinical assistant professor in Psychiatry Jack Peltz, Ph.D., the study, recently published in Sleep Health, not only reinforces the theorized link between sleep and adolescent mental health, but is among the first to demonstrate that school start times may have a critical impact on adolescent sleep and daily functioning. The findings provide additional evidence in the national debate over how school start times impact adolescent health.

    “Our study is consistent with a growing body of research demonstrating the close connection between sleep hygiene and adolescent mental health,” says Peltz, who is also on the faculty of Daemon College in Amherst, N.Y. “But ours is the first to really look at how school start times affect sleep quality, even when a teen is doing everything else right to get a good night’s sleep. While there are other variables that need to be explored, our findings show that earlier school start times seem to put more pressure on the sleep process and increase mental health symptoms, while later school start times appear to be a strong protective factor for teens.”

    Peltz is one of many investigators now exploring ways to address what has become a nationwide sleep epidemic among adolescents. About 90% of high-school-aged adolescents get insufficient sleep on school nights, or barely meet the required amount of sleep (8-10 hours) needed for healthy functioning. School start times, among other interventions (ie. limiting electronic use before bedtime), have become a critical point of interest. The research to date, however, has primarily focused on the academic benefits of delaying school start times for adolescents, rather than examining how earlier start times may disrupt sleep-related processes and affect mental health outcomes, says Peltz.

    “Looking at school start times as a larger contextual variable that may moderate sleep hygiene, sleep quality and adolescent functioning, fills an important gap in the literature,” he says.

    With the help of a grant from the National Sleep Foundation, Peltz’ and his co-authors used an online tool to collect data from 197 students across the country between the ages of 14 and 17. All children and parents completed a baseline survey that included questions about the child’s level of sleep hygiene, family socioeconomic status, their circadian chronotype (roughly, whether you are a “morning person” or “night person”), and their school start times. They were separated into two groups: those who started school before 8:30 a.m. and those who started after 8:30 a.m. (which is currently the recommended start time for high schoolers by the American Academy of Pediatricians).

    Over a period of seven days, the students were instructed to keep a sleep diary, in which they reported specifically on their daily sleep hygiene, levels of sleep quality and duration, and their depressive/anxiety symptoms.

    The results showed that good baseline sleep hygiene was directly associated with lower average daily depressive/anxiety symptoms across all students, and the levels were even lower in students with school start times after 8:30. However, students with good baseline sleep hygiene and earlier school start times had higher average daily depressive/anxiety symptoms.

    “Our results suggest that good sleep hygiene practices are advantageous to students no matter when they go to school,” says Peltz. “Maintaining a consistent bedtime, getting between 8 and 10 hours of sleep, limiting caffeine, turning off the TV, cell phone and video games before bed… these efforts will all benefit their quality of sleep and mental health. However, the fact that school start times showed a moderating effect on mental health symptoms, suggests that better sleep hygiene combined with later school start times would yield better outcomes.”

    Peltz says one possible explanation for the difference may be that “earlier starting students” have more pressure on them to get high quality sleep, or there may be other aspects of the school environment that vary by start time that may trigger their depression/anxiety symptoms. Peltz says there may be other lifestyle changes that coincide with earlier start times as well (for example, morning nutrition or exercise) that require closer scrutiny.

    “More studies are definitely needed, but our results help clarify the somewhat mixed findings with other sleep hygiene-focused interventions, by suggesting that school start times may be a very important contextual factor,” he says.

    Peltz hopes the evolving evidence in this area will help propel more concrete national sleep hygiene recommendations for children and teens, similar to what the American Dental Association recommends for oral health.

    “If we don’t sleep, eventually we will die…our brains will cease to function,” he says. “At the end of the day, sleep is fundamental to our survival. But if you have to cram for a test or have an important paper due, it’s one of the first things to go by the wayside, although that shouldn’t be.”


  6. Study suggests doing homework is associated with change in students’ personality

    October 12, 2017 by Ashley

    From the Universität Tübingen press release:

    Homework may have a positive influence on students’ conscientiousness. As results of a study conducted by University of Tübingen researchers suggest, students who do more homework than their peers show positive changes in conscientiousness. Thus, schools may be doing more than contributing to students’ learning, but they may also be effecting changes of their students’ personality. The study results were published in the Journal of Research in Personality.

    Previous research finds that homework effort is consistently related to student achievement. Also, conscientiousness appears to be the most important personality trait for predicting homework effort. With this connection in mind, proponents of homework have argued that the effort which students invest in their homework may have positive effects on students by influencing their conscientiousness. In their study, the Tübingen scientists investigated whether this claim holds true.

    They analyzed data from a longitudinal study with 2,760 students from two different school tracks in the German states of Baden-Württemberg and Saxony. Students were initially assessed right after their transition from primary to secondary school in Grade 5. For the next three years, students were assessed annually between six and eight weeks after the start of each school year. They answered questions such as how many of their last 10 homework assignments in mathematics and German they did as well as possible. Also, they were asked how conscientious they thought they were including whether they would describe themselves as tidy or rather as messy and negligent. In addition to students’ self-reports, parents were asked to assess their children’s conscientiousness as well.

    Results show that those students who invested a lot of effort in their homework between Grades 5 and 8 also profited in terms of their conscientiousness. Previous research has shown that conscientiousness tends to undergo a temporary dip in late childhood and early adolescence. As the results found by the Tübingen scientists suggest, doing your homework thoroughly and meticulously appeared to counterbalance this dip. Indeed, researchers found a substantial decrease in conscientiousness for students who reported that they had not made an effort with their homework. Those results were also backed by parents, whose reports matched those of their children.

    “Our results show that homework is not only relevant for school performance, but also for personality development — provided that students put a lot of effort into their assignments,” says Richard Göllner, first author of the study. “The question whether doing your homework can also influence the development of conscientiousness has been mostly neglected in previous discussions of the role of homework,” criticizes Ulrich Trautwein, director of the Hector Research Institute of Education Sciences and Psychology. “We need to define more precisely what expectations we have of the potential of homework and how those expectations can be fulfilled.”


  7. Study suggests teens’ online friendships just as meaningful as face-to-face ones

    October 6, 2017 by Ashley

    From the University of California, Irvine press release:

    Many parents worry about how much time teenagers spend texting, sharing selfies and engaging in other online activities with their friends. However, according to a recent research synthesis from the University of California, Irvine, many of these digital behaviors serve the same purpose and encompass the same core qualities as face-to-face relationships.

    “Increased peer interaction in cyberspace has led to growing concern that today’s adolescent friendships are now less intimate and an inadequate substitute for those back in the day that took place in person,” said Stephanie Reich, UCI associate professor of education and co-author of the study. “Many contacts between adolescents are mediated through technology and can provide additional opportunities for friends to spend time together, share thoughts and display affection than in offline spaces alone.”

    Reich, along with Ph.D. student and lead author Joanna Yau, identified six core characteristics of offline friendships — self-disclosure, validation, companionship, instrumental support, conflict and conflict resolution — and their digital parallels. For each quality, they noted ways in which online interfaces corresponded with or differed from in-person communication. The results are detailed in the May issue of Adolescent Research Review.

    Reich and Yau found that digital exchanges offer more benefits in some areas and carry increased risks in others. On the plus side, online contact enhances companionship between friends via conversations that can continue throughout the day and night without disrupting others, and it also allows more time to control emotions and calm down before crafting and sending a response to something upsetting. Conversely, friendships can be damaged by gossip and rumors, which spread much faster and farther through cyberspace.

    “Digital communication may increase the ramifications of conduct due to the permanence of information and the speed by which it travels, but at the core, friendships seem to have the same key characteristics,” Reich said. “The majority of adolescents interact electronically most often with individuals they consider friends offline. So rather than reducing intimacy in these relationships, technology-mediated communication may provide additional benefits to teens as connections occur both face-to-face and online.”


  8. Study suggests teens’ ability to consider the intentions of others linked to structural changes in the brain

    September 21, 2017 by Ashley

    From the Dartmouth College press release:

    When it comes to the concept of fairness, teenagers’ ability to consider the intentions of others appears to be linked to structural changes underway in the brain, according to a Dartmouth-led study published by Scientific Reports. The study is the first to provide evidence linking structural changes with behavioral changes within this context. (See video: https://youtu.be/uLv5da5wvus.) Understanding the intentions of others is fundamental to human cooperation and how we exist as social beings.

    Understanding the intentions of others is fundamental to human cooperation and how we exist as social beings. Previous studies have demonstrated that certain areas of the social brain relating to how we care about others or “social inference,” continue to undergo cortical development until late adolescence. As demonstrated by the following time-lapse video, these changes include the thinning of the brain’s cortex, which likely reflect synaptic reorganization in how brain regions are connected and communicate with each other. The study is the first to provide evidence linking structural changes with behavioral changes in the brain within the context of fairness concerns.

    For the study, participants between nine and 23-years old took part in an ultimatum game based on the exchange of money. Proposers first selected between two different divisions of $10, and responders then decided whether to accept or reject the chosen division. Researchers evaluated how participants used two different cognitive strategies when making their decision using computational modeling, and then investigated how these processes correlated with measurements of participants’ cortical thickness, as obtained through magnetic resonance imaging (MRI).

    Younger players tended to want to minimize the difference in the division of the money, whereby everyone gets the same amount but as players became older, they were more inclined to consider the other player’s intentions. This shift from a simple rule-based egalitarian strategy to a more sophisticated strategy that considers both the other player’s intentions and notions of reciprocity, was observed during late adolescence. This gradual shift coincided with cortical thinning in the brain, specifically, in areas of the dorsomedial prefrontal cortex, which is involved with how we view others’ mental states, and posterior temporal cortex, which is involved in visual perception particularly in processing facial information.

    “This work provides converging evidence in line with other research that the computation of inferring intentions is processed in the dorsomedial prefrontal cortex,” said senior author Luke Chang, an assistant professor in the Department of Psychological and Brain Sciences and the director of the Computational Social Affective Neuroscience Laboratory (Cosan Lab) at Dartmouth. “We were surprised that this shift in preference for considering others’ intentions occurred so late in development. Of course, younger children can infer the intentions of others, but we see that this ability continues to be refined well into late adolescence. This finding has potential implications regarding how much autonomy this age group should be given when making important social and ethical decisions, such as purchasing weapons, going to war, and serving on juries,” added Chang.


  9. Close friendships in high school predict improvements in mental health in young adulthood

    September 4, 2017 by Ashley

    From the Society for Research in Child Development press release:

    Adolescence is a time of social challenges and changing expectations. While relationships with peers may be important for youth at this time, do they also have implications over time? A new longitudinal study suggests that the types of peer relationships youth make in high school matter for mental health through young adulthood. The study, authored by researchers at the University of Virginia, is published in the journal Child Development.

    “Our research found that the quality of friendships during adolescence may directly predict aspects of long-term mental and emotional health,” according to Rachel K. Narr, PhD candidate in clinical psychology at the University of Virginia, who led the study. “High school students with higher-quality best friendships tended to improve in several aspects of mental health over time, while teens who were popular among their peers during high school may be more prone to social anxiety later in life.”

    The study looked at a community sample of 169 adolescents over 10 years, from the time they were age 15 to when they were 25. The youth were racially, ethnically, and socioeconomically diverse, with 58% Caucasian, 29% African American, and 8% of mixed race/ethnicity, and with median family income $40,000 to $59,999. Adolescents were assessed annually, answering questions about who their closest friends were, reporting on their friendships, and participating in interviews and assessments exploring such feelings as anxiety, social acceptance, self-worth, and symptoms of depression; teens’ close friends also reported on their friendships and were interviewed.

    High-quality friendships were defined as close friendships with a degree of attachment and support, and those that allow for intimate exchanges. Friendship quality was determined from reports by participants’ best friends at age 15. Popularity was defined as the number of peers in the teens’ grade who ranked them as someone they would like to spend time with, and was measured using nominations from all the teens.

    Researchers found that teens who prioritized close friendships at age 15 had lower social anxiety, an increased sense of self-worth, and fewer symptoms of depression by the time they reached age 25 than their peers. Conversely, teens who were broadly sought after in high school — that is, those who were popular among their peers — had higher levels of social anxiety as young adults.

    Neither having a strong best friendship nor being more popular predicted short-term changes in mental health, the researchers note. These differences only became apparent later and they appeared regardless of youth’s experiences in the interim.

    The study’s conclusion: Experiencing strong, intimate friendships during adolescence may help promote long-term mental health. The researchers suggest that this may be because positive experiences with friends help bolster positive feelings about oneself during a stage of life when personal identity is being developed. Also, close friendships may set adolescents on a trajectory to expect and therefore encourage supportive experiences in the future.

    The study also determined that there was a low relation between teens having high-quality friendships and being more sought after by their peers, suggesting that although some teens manage both popularity and close friendship well, and attract both due to similar characteristics, for the most part, these two types of social success are due to different personal attributes.

    “Our study affirms that forming strong close friendships is likely one of the most critical pieces of the teenage social experience,” explains Joseph Allen, Hugh P. Kelly Professor of Psychology at the University of Virginia, who coauthored the study. “Being well-liked by a large group of people cannot take the place of forging deep, supportive friendships. And these experiences stay with us, over and above what happens later. As technology makes it increasingly easy to build a social network of superficial friends, focusing time and attention on cultivating close connections with a few individuals should be a priority.”


  10. Peer influence doubles smoking risk for adolescents

    September 2, 2017 by Ashley

    From the University of Pennsylvania press release:

    The way things stand now, tobacco use will kill one billion people in the 21st century. In the United States, 90 percent of smokers pick up the habit by age 18, making adolescence a critical time for smoking-prevention efforts.

    Peer influence has long been known as a major risk factor for adolescent smoking, but findings have varied about how big the risk is or how this dynamic unfolds. A new, rigorous meta-analysis of 75 longitudinal teen smoking studies published today in the journal Psychological Bulletin finds that having friends who smoke doubles the risk that children ages 10 to 19 will start smoking and continue smoking. It also found that peer influence is more powerful in collectivist cultures than in those where individualism is the norm.

    There has been a great deal of research about peer influences on adolescents, says the study’s senior author, Dolores Albarracín, PhD, a professor of psychology at the University of Illinois at Urbana-Champaign, but often findings rely on individual studies. “Meta-analysis is a summary of all we know,” she says, “giving us a more reliable, robust number that is better supported by the facts.”

    “One of our most intriguing findings is that culture actually matters in how much influence adolescents have on their peers,” says the study’s lead author, Jiaying Liu, PhD, a recent graduate of the Annenberg School for Communication at the University of Pennsylvania. “Meta-analysis allowed us to examine studies from across the globe. We predicted that people in collectivistic cultures would be more likely to be influenced by peers around them, and that held true. In those most collectivistic countries, adolescents whose peers smoke are 4.3 times more likely to pick up smoking compared to people who have no peers smoking. By contrast, having peers who smoke made adolescents from those most individualist countries 1.89 times more likely to smoke.”

    The study included data from 16 countries, both collectivistic — for example, China, South Korea, Jordan and Portugal — and individualistic like the United States, Australia, Canada, the Netherlands and the United Kingdom.

    The authors also examined the ethnic origins of the adolescents in each study, regardless of nationality. “We found that peer influence was much weaker in samples with higher proportions of adolescents with a European background, but much stronger in samples with higher proportions of adolescents with an Asian background,” Liu says.

    This finding about ethnic and cultural background may also explain why the results of teen smoking studies have varied in how big an effect peer influence has.

    In addition, the study found that closer friends were more likely to influence peers to start smoking when compared to more distant friends. The closeness of peer friendships did not impact whether adolescents who smoke continued to smoke, however, indicating that perhaps the addictive nature of tobacco was an overriding factor.

    The study was also able to better avoid what is often seen as the “chicken or the egg” problem of peer influence smoking studies: Do teens influence one another to smoke, or do those who smoke simply tend to become friends?

    “By including only longitudinal studies, where peer influence was measured at an earlier time and adolescent smoking outcomes at a later date, we were better able to establish that peer influence led to the adolescent smoking outcomes, rather than the other way around,” says Liu, who will be starting in the fall as an assistant professor in the University of Georgia’s Department of Communication Studies.

    The researchers hope that by providing a better understanding of the risk factors for teen smoking, they can help inform more targeted prevention efforts. By knowing who is most at risk, parents and public health officials alike can give teenagers the tools to resist tobacco.

    “It’s not enough just to say, ‘Don’t smoke it’s bad for you,'” says Albarracín. “How are teenagers going to deal with temptation on a daily basis? We need much more specific campaigns dealing with normative influence — for example, pointing out how many adolescents don’t smoke. There can be more messaging in schools and training for parents on how to build refusal skills in their children.”

    Peer influence is particularly strong in the adolescent years, as children reduce the amount of time spent with parents and increase the amount of unsupervised time spent with peers.

    “This work highlights the importance of considering the networks that surround teens, not just thinking about individuals in isolation,” says co-author Emily Falk, PhD, associate professor at Penn’s Annenberg School for Communication and director of its Communication Neuroscience Lab. “Behaviors spread from person to person, and keeping that in mind is essential for prevention and cure.”

    “The burden of smoking-caused morbidity is heavy around the world,” Liu adds. “If social influence is a crucial factor in adolescents’ decisions to start smoking and keep smoking, we want to understand how to leverage its power for better smoking prevention. It’s always easier to stop people from starting to smoke than to change their behavior later in life.”