Category: Child Psychology

Women who have a fear of childbirth spend longer in labour than women who have no such fear, suggests new research published June 27 in BJOG: An International Journal of Obstetrics and Gynaecology.

Between 5 and 20% of pregnant women have a fear of childbirth. Various factors have been associated with increased prevalence of fear of childbirth, including young maternal age, being a first-time mother, pre-existing psychological problems, lack of social support and a history of abuse or adverse obstetric events.

This Norwegian study looked at 2206 women with a singleton pregnancy who intended to deliver vaginally.

Fear of childbirth was assessed by the Wijma Delivery Expectancy Questionnaire (W-DEQ), a validated psychometric instrument designed to measure fear of childbirth. Women undertook the questionnaire at 32 weeks gestation and fear of childbirth was defined as a score of more than 85. Out of the total number, 165 (7.5%) women scored more than 85.

Labour duration was defined as 3-4 centimetres cervical dilatation and 3 uterine contractions per 10 minutes, until delivery of the child.

The average age of the participants at delivery was 30.9 years and 50.5% (1113 women) were first time mothers. Average labour duration was 8.22 hours for first-time mothers, and it was 4.91 hours for parous women.

The researchers found that women with a fear of childbirth spent one hour and 32 minutes longer in labour than women with no such fear. After adjustment for other factors associated with labour duration, such as parity, epidural analgesia, instrumental vaginal delivery and labour induction, the difference was still significant at 47 minutes.

Average labour duration was 8 hours for women with fear of childbirth compared to 6.46 hours (which equals 6 hours and 28 minutes) for women without fear.

The study also found that women with fear of childbirth more often delivered by instrumental vaginal delivery (17.0% versus 10.6%) or emergency caesarean delivery (10.9% versus 6.8%) as compared to women without fear of childbirth.

In total, 25.5% (42 women) of women with fear of childbirth and 44.4% (906 women) of women without fear of childbirth had a vaginal delivery without any obstetric interventions.

However, despite increased labour duration for women with a fear of childbirth, a large proportion of women achieved a vaginal delivery which was their intention compared to women with no fear (89.1% versus 93.2%).

Samantha Salvesen Adams, Health Services Research Centre, Akershus University Hospital, University of Oslo, Norway and co-author of the research said:

"Fear of childbirth seems to be an increasingly important issue in obstetric care. Our finding of longer duration of labour in women who fear childbirth is a new piece in the puzzle within this intersection between psychology and obstetrics.

"We found a link between fear of childbirth and longer duration of labour. Generally, longer labour duration increases the risk of instrumental vaginal delivery and emergency caesarean section. However, it is important to note that a large proportion of women with a fear of childbirth successfully had a vaginal delivery and therefore elective caesarean delivery should not be routinely recommended."

John Thorp, BJOG Deputy-Editor-in-Chief added:

"There are a number of reasons why women may develop a fear of childbirth. This research shows that women with fear of childbirth are more likely to need obstetric intervention and this needs to be explored further so that obstetricians and midwives can provide the appropriate support and advice."

Spending money on activities and events, such as concert tickets or exotic vacations, won't make you happier if you're doing it to impress others, according to findings published in the Journal of Happiness Studies.

Research has shown that consumers gain greater happiness from buying life experiences rather than material possessions, but only if they choose experiences for the right reasons says the new study.

"Why you buy is just as important as what you buy," said Ryan Howell, assistant professor of psychology at San Francisco State University. "When people buy life experiences to impress others, it wipes out the well-being they receive from the purchase. That extrinsic motivation appears to undermine how the experiential purchase meets their key psychological needs."

The study builds on Howell's previous findings, which suggest that people who buy life experiences are happier because experiential purchasing helps fulfill psychological needs that are vital for human growth and well-being. These include the need to feel competent, autonomous — or self-directed — and connected to others.

For the present study, Howell and colleagues surveyed 241 participants and found that a person's motivation for making a purchase predicts whether these needs will be met. Howell conducted the research with Jia Wei Zhang, a student in his lab, and University of Rochester researcher Peter Caprariello.

They found that people who choose to buy life experiences because it is in line with their desires, interests and values reported a greater sense of fulfillment and well-being. They felt more autonomous, competent and connected to others, less loneliness and a greater sense of vitality.

Individuals who choose life experiences to gain recognition from others reported feeling less autonomous, competent and connected to others.

"The biggest question you have to ask yourself is why you are buying something," Howell said. "Motivation appears to amplify or eliminate the happiness effect of a purchase."

As part of the study, the researchers developed and validated a new survey to measure individuals' motivations for experiential buying. Members of the public can take the survey by visiting the "Beyond the Purchase" website. Howell and colleagues launched the website to collect data for academic studies and allow members of the public to take free psychology quizzes to find out what kind of shopper they are and how their spending choices affect them. Visit the Beyond the Purchase website at http://www.beyondthepurchase.org

 From Top 40 hits to baby names, styles change and fashions evolve over time. While the latest fad may seem arbitrary, new research suggests that basic psychological processes can explain why some things become popular.

In a study forthcoming in Psychological Science, a journal of the Association for Psychological Science, researcher Jonah Berger, from the University of Pennsylvania, and his colleagues investigated whether trends in baby names could help us to understand how and why things become popular over time.

"We were interested in understanding cultural evolution or whether it is possible to predict what things will become popular next," said Berger. "Songs, movies, and first names often become popular, but little is known about why some things become more popular than others."

The researchers hypothesized that specific psychological processes — such as our preference for things that seem familiar — might explain large-scale cultural trends.

The scientists used data from the US Social Security Administration to collect the first names of babies born between 1882 and 2006. Using the over seven thousand names they collected, they broke the names down into phonemes, or distinct units of sound. For example, the name 'Karen' can be broken down into 'K EH R AH N.' The phonemes from each year were compared to determine if there were any correlations between phoneme popularity and name popularity.

The researchers discovered that names were more popular when the phonemes that make up the name were popular in other names the previous year. So the name Karen probably became popular in 2000 because names that began with the K sound, ended with the N sound, or had a EH, R or AH sound in the middle of the name were popular in 1999.

"The similarity between cultural items influenced what became popular next," said Berger. "If the name Katie was popular, similar sounding names like Karen, Carl, and Katrina were more likely to become popular in the future."

To demonstrate that an increase in hearing a particular phoneme could influence the popularity of names that shared that phoneme, Berger and his colleagues did a second study in which they looked for correlations between phonemes in hurricane names and baby names. When hurricanes cause substantial damage, their names are mentioned more frequently, exposing more people to the phonemes in the name. They found that the names of more destructive hurricanes influenced the popularity of certain phonemes in baby names after the storm. For example, after Hurricane Katrina — the Category 5 storm that wreaked havoc on the Gulf Coast — there was a 9% increase in names that began with the letter 'K.'

Overall, the findings provide insight into how culture evolves over time. Songs, movies, and technology may not become popular based on their unique characteristics, but because they share common features with other popular items, whether it's a similar look, sound, or name.

From factory workers to Wall Street bankers, a reasonable proficiency in math is a crucial requirement for most well-paying jobs in a modern economy. Yet, over the past 30 years, mathematics achievement of U.S. high school students has remained stagnant — and significantly behind many other countries, including China, Japan, Finland, the Netherlands and Canada.

A research team led by Carnegie Mellon University's Robert Siegler has identified a major source of the gap — U. S. students' inadequate knowledge of fractions and division. Although fractions and division are taught in elementary school, even many college students have poor knowledge of them. The research team found that fifth graders' understanding of fractions and division predicted high school students' knowledge of algebra and overall math achievement, even after statistically controlling for parents' education and income and for the children's own age, gender, I.Q., reading comprehension, working memory, and knowledge of whole number addition, subtraction and multiplication. Published in Psychological Science, the findings demonstrate an immediate need to improve teaching and learning of fractions and division.

"We suspected that early knowledge in these areas was absolutely crucial to later learning of more advanced mathematics, but did not have any evidence until now," said Siegler, the Teresa Heinz Professor of Cognitive Psychology at Carnegie Mellon. "The clear message is that we need to improve instruction in long division and fractions, which will require helping teachers to gain a deeper understanding of the concepts that underlie these mathematical operations. At present, many teachers lack this understanding. Because mastery of fractions, ratios and proportions is necessary in a high percentage of contemporary occupations, we need to start making these improvements now."

The research, supported by grants from the U.S. Department of Education's Institute of Education Sciences and by the National Science Foundation's Developmental and Learning Science Group at the Social, Behavioral, and Economic Directorate, was conducted by a team of eight investigators: Siegler; U.C. Irvine's Greg J. Duncan; the University of Michigan's Pamela E. Davis-Kean, Maria Ines Susperreguy and Meichu Chen; the University of London's Kathryn Duckworth; the University of Chicago's Amy Claessens; and Vanderbilt University's Mimi Engel.

For the study, the team examined two nationally representative data sets, one from the U.S. and one from the United Kingdom. The U.S. set included 599 children who were tested in 1997 as 10-12 year-olds and again in 2002 as 15-17-year-olds. The set from the U.K. included 3,677 children who were tested in 1980 as 10-year-olds and in 1986 as 16-year-olds. The importance of fractions and division for long-term mathematics learning was evident in both data sets, despite the data being collected in two different countries almost 20 years apart.

"This research is a good demonstration of what collaborations between psychologists, economists, public policy analysts and education scientists can create," said Davis-Kean, associate professor of psychology at Michigan. "Instead of relying on results from a single study, this study replicates findings across two national data sets in two different countries, which strengthens our confidence in the results."

Rob Ochsendorf, program officer for special education research at the U.S. Department of Education's Institute of Education Sciences added, "This study is critical for providing empirical and general confirmation of the crucial role of division and fractions proficiency for long-term success in mathematics for all students. The results provide important cues to educators and researchers regarding the skills that are ripe for intervention in order to improve overall mathematics achievement in the U.S."

— If your father and grandfather waited until they were older before reproducing, you might experience life-extending benefits. Biologists assume that a slow pace of aging requires that the body invest more resources in repairing cells and tissues.

A new Northwestern University study suggests that our bodies might increase these investments to slow the pace of aging if our father and grandfather waited until they were older before having children.

"If your father and grandfather were able to live and reproduce at a later age, this might predict that you yourself live in an environment that is somewhat similar — an environment with less accidental deaths or in which men are only able to find a partner at later ages," said Dan T.A. Eisenberg, lead author of the study and a doctoral candidate in anthropology at Northwestern. "In such an environment, investing more in a body capable of reaching these late ages could be an adaptive strategy from an evolutionary perspective."

Christopher W. Kuzawa, co-author of the study, associate professor of anthropology at Northwestern and a faculty fellow at the University's Institute for Policy Research, said the new findings are fascinating.

"If our recent ancestors waited until later in adulthood before they reproduced, perhaps for cultural reasons, it would make sense for our bodies to prepare for something similar by investing the extra resources necessary to maintain healthy functioning at more advanced ages," Kuzawa said.

The study, which was conducted in the Philippines, found that children of older fathers not only inherit longer telomeres, which are DNA found at the ends of chromosomes, but that the association of paternal age with offspring telomere length is cumulative across multiple generations. Shorter telomeres seem to be a cause of ill health that occurs with aging — longer telomeres seem to promote slower aging.

It appears that as men delay reproduction, they will pass on longer telomeres to offspring, which may facilitate extension of life span and allow reproducing at older ages.

Eisenberg said he hopes the study will further our understanding of the evolution of aging, why we get old and the ways that we adapt to the environment.

"When we think of adaptation, we tend to think of it happening over hundreds of generations," Eisenberg said. "This study illustrates a means by which much more rapid adaptive genetic changes might occur over just a few generations."

"The idea that information about the environment can be passed on biochemically from one generation to the next is certainly not something new," said M. Geoffrey Hayes, co-author of the study, assistant professor of medicine at Northwestern's Feinberg School of Medicine and assistant professor of anthropology at Northwestern. "But what is quite unique in the case of our telomere study is that we're seeing an association across more than one generation."

The researchers said their study should not be taken as a recommendation that men reproduce at later ages as previous research has shown that older fathers are more likely to pass along harmful mutations to their offspring at conception, which can lead to increased rates of miscarriage and other health issues in offspring.

However, Kuzawa said, "These new findings suggest that there might also be underappreciated benefits to having an older father or grandfather."

And while the findings are fascinating, Kuzawa said they will need to see if they are replicated in other populations.

"We will want to see if the longer telomeres that offspring of older fathers and grandfathers inherit at birth have fewer health problems and ailments as they age," Kuzawa said. "Based upon our findings, we predict that this will be the case, but this is a question to be addressed in future studies."

 Religious practices that strongly control female sexuality are more successful at promoting certainty about paternity, according to a study published in the current issue of the Proceedings of the National Academy of Sciences.

The study analyzed genetic data on 1,706 father-son pairs in a traditional African population — the Dogon people of Mali, West Africa — in which Islam, two types of Christianity, and an indigenous, monotheistic religion are practiced in the same families and villages.

"We found that the indigenous religion allows males to achieve a significantly lower probability of cuckoldry — 1.3 percent versus 2.9 percent," said Beverly Strassmann, lead author of the article and a biological anthropologist at the University of Michigan.

In the traditional religion, menstrual taboos are strictly enforced, with women exiled for five nights to uncomfortable menstrual huts. According to Strassmann, the religion uses the ideology of pollution to ensure that women honestly signal their fertility status to men in their husband's family.

"When a woman resumes going to the menstrual hut following her last birth, the husband's patrilineage is informed of the imminency of conception and cuckoldry risk," Strassmann said. "Precautions include postmenstrual copulation initiated by the husband and enhanced vigilance by his family."

Across all four of the religions practiced by the Dogon people, Strassmann and colleagues detected father-son Y DNA mismatches in only 1.8 percent of father-son pairs, a finding that contradicts the prevailing view that traditional populations have high rates of cuckoldry. A similar rate of cuckoldry has been found in several modern populations, but a key difference is that the Dogon do not use contraception.

The study, which was supported by funding from the National Science Foundation, is part of Strassmann's ongoing, 26-year study of the Dogon people.

"The major world religions sprang from patriarchal societies in which the resources critical to reproduction, whether in the form of land or livestock, were inherited from father to son down the male line," Strassmann and colleagues write. "Consistent with patrilineal inheritance, the sacred texts set forth harsh penalties for adultery and other behaviors that lower the husband's probability of paternity. The scriptures also place greater emphasis on female than on male chastity, including the requirement of modest attire for women and the idealization of virginity for unmarried females."

While previous studies have examined the evolutionary biology of patriarchy through primate antecedents or cultural factors, the current study is the first to investigate whether religions that more strongly regulate female sexuality are more successful at limiting the incidence of cuckoldry.

"Although world religions do not have menstrual huts, they do share many tenets that may foster cuckoldry avoidance," the authors write. "For example, in Judaism, menstrual purity laws increase coital frequency around the time of ovulation. In Islam, paternity confusion is prevented by the Qur'an's rule that, after divorce, a woman must wait for three menstrual periods before remarrying. The Hindu text, 'The Laws of Manu,' admonishes against cuckoldry or 'sowing in another man's field.'

"Strong statements against adultery and extramarital children are found in the Bible and, in Buddhism, adultery is a form of sexual misconduct. In preventing cuckoldry, religions use the dual strategy of social control in the public sphere (attendance at a place of worship or at a menstrual hut) and the fear of divine or supernatural punishment. In the United States, frequent church attendance and belief that the Bible is the word of God were the two most robust predictors of lower rates of self-reported extra-partner copulations."

In short, Strassmann and colleagues maintain that the ideological and tactical similarities between these world religions and the Dogon religion have arisen in response to the same biological pressures. Religious patriarchy is directly analogous to the mate-guarding tactics used by animals to ensure paternity.

By participating in a peer- and community-driven education program, a new study offers evidence supporting community-based intervention as a successful vehicle to encourage high school students in Appalachia to reduce their intake of sugared drinks.

The study, supported by funding from the Ohio State Center for Clinical and Translational Science (CCTS) and published in PRISM: A Journal of Regional Engagement was built around a 30-day "challenge" which utilized academic-community partnerships to identify health needs and promote positive health through community-led interventions in Appalachia.

"An estimated 24.8 million people live in Appalachia, and this population often has the highest concentrations of chronic illnesses like diabetes and obesity," said Laureen Smith, PhD, RN, study investigator and assistant professor in the College of Nursing. "It's our hope that early intervention will help prevent disease in Appalachia and we can reapply what we learn here to populations outside of Appalachia." Through an integrated model that utilized surveys, focus groups and community health advocates, Smith noticed a recurring theme throughout both communities: there was a growing concern regarding teens' consumption of sugar sweetened beverages (SSBs). From there, a pilot project was born. Dubbed "Sodabriety," the project challenged high school students to give up or significantly reduce their consumption of SSBs for 30 days.

Smith, along with co-investigator, Mary Ellen Wewers, PhD, MPH, professor and associate dean for research in the College of Public Health, worked closely with the Pike Healthy Lifestyle Initiative, academic partners and community residents and stakeholders to spearhead the project that would explore teenage consumption of SSBs while determining the effectiveness of community-based intervention in both urban and rural Appalachia.

The 30-day challenge required a pre-test/post-test design to enable the tracking of long-term impact. Along with a social marketing campaign, a commercial and a "kick off kit," students were given surveys and asked to maintain a daily beverage log. At the close of the challenge, students saw a significant reduction in their SSB consumption and an increase in their water consumption.

"I think the kids really engaged with the program because they were able to have a voice in the way the information was shared. They motivated each other in ways that showed a sense of ownership and pride," says Smith.

The study was conducted using a Community Based Participatory Research (CBPR) approach which engages the community in each step of research, something that Smith says was key to the program's success.

"Using CBPR we were able to gather accurate, comprehensive and dependable data about the community's health while showcasing the successful impact this method can have when establishing effective and trusting relationships between researchers and the community," said Smith. "Most notably, the community-based approached empowered Appalachian residents to cultivate and deliver a viable health program that will impact the health and wellness of residents in the future."

In response to the success of "Sodabriety," Smith secured funding to implement similar interventions in three additional Pike County schools.

The study is part of the Administrative Supplement project, "Engaging Urban and Rural Appalachian Communities in Clinical Research." As part of the Appalachian Translational Research Network, CCTS is committed to furthering the research and understanding of Appalachian culture through projects that focus on religiosity, health outlooks and research perceptions of the Appalachian community.

The project described was supported by Award Number UL1RR025755 from the National Center for Advancing Translational Sciences of the National Institutes of Health.

Skin cancer patients whose childhood included periods of neglect or maltreatment are at a much greater risk for their cancers to return when they face a major stressful event, based on a new study.

The research suggests that such experiences during a person's youth can set a lower level of immune response for life, which in turn might make them more susceptible to the kind of cancers that are often successfully fought by the immune system, so-called immunogenic tumors.

While the research focused on patients with a fairly benign form of skin cancer — basal cell carcinoma (BCC) — the findings appear as a warning for patients to be more vigilant in concerns over their health for the rest of their lives.

The study appears in the June 4, 2012, issue of the journal Archives of General Psychiatry and is the latest in three decades of research linking stress and immunity that have been led by investigators at Ohio State University's Institute for Behavioral Medicine Research (IBMR).

"This is the first study to show that troubled early parental experiences, in combination with a severe life event in the past year, predict local immune responses to a BCC tumor," wrote Christopher Fagundes, first author of the paper and a postdoctoral fellow at the IBMR.

"This expands the growing evidence that the consequences of early parental experiences extend well beyond childhood."

Basal cell tumors are considered the most common form of skin cancer, and much less dangerous than squamous cell carcinomas or melanomas. And their frequency is on the rise, the number having doubled in the United States every 14 years. Nearly half of all BCC patients will have an additional tumor form within three years of their first.

The researchers looked at 91 men and women who previously had a BCC. Each of the participants were given a battery of surveys and interviews, some of which gauged their past relationship with their parents as children. From this, the researchers could measure the degree of neglect or maltreatment the patients had experienced as children.

Tissue from each participant's tumors was also analyzed and tested for the presence of four types of messenger RNA, markers that measured the intensity of the person's immune response to their tumor.

The results showed that BCC patients who had a severe, stressful life event in the last year, and who experienced neglect or maltreatment from their mothers as children, had a substantial drop in their immune response to the tumors.

"Those in the top 25 percent of maltreatment by their mothers saw a 350 percent reduction in immunity compared to those in the bottom 25 percent of maltreatment," Fagundes explained.

Maltreatment or neglect from the father showed a 140 percent drop in immunity when the top 25 percent were compared to the bottom 25 percent, he said.

"We're not talking about abuse here," he explained. "And the effects were similar regardless of whether the harm came from the mother or father."

Jan Kiecolt-Glaser, co-author of the paper and a professor of psychiatry and psychology at Ohio State, said, "This means that for people who have had an early history of vulnerability and who are currently going through a stressful period, they have another reason to watch their health and be especially vigilant."

The findings are likely to be significant beyond just their role with BCC patients, said Ron Glaser, another co-author and director of the IBMR. Glaser, a professor of molecular virology, immunology and medical genetics, pointed to other immunogenic cancers that might be affected.

"If the immune system is down-regulated, it will affect a person's ability to deal with that tumor," he said. "Some examples of other immunogenic tumors include ovarian cancer, head and neck cancers, melanoma, some lymphomas and tumors induced by cancer viruses, and renal cell tumors."

The researchers hope to continue the work and determine what mechanisms are responsible for the continued lower immune response.

Support for this work came from the National Cancer Institute and the American Cancer Society.

The family meal is often touted and encouraged for its social and health benefits, but a new Cornell University study questions the nature of this association, finding that the perceived benefits may not be as strong or as lasting once a number of factors are controlled for.

"We find that most of the association between family meals and teen well-being is due to other aspects of the family environment. Analyses that follow children over time lend even weaker evidence for causal effects of family meals on adolescent and young adult well-being," said Kelly Musick, associate professor of policy analysis and management at Cornell and lead author of "Assessing Causality and Persistence in Associations Between Family Dinners and Adolescent Well-Being," to be published in the June edition of the Journal of Marriage and Family.

Musick and co-author Ann Meier, associate professor of sociology at the University of Minnesota, found that the ability to manage a regular family dinner is in part facilitated by family resources such as time and money, and in part a proxy for other family characteristics, including time together, closeness, and communication. Families with both biological parents present, a non-employed mother, higher income, and better family relationships ate together more frequently. Controlling for the quality of family relationships in particular explained much of the family dinner's association with teen depressive symptoms, substance use, and delinquency — three factors typically examined in family meal studies. Only some of these associations held up to analyses of adolescent outcomes over time.

The study accounts for aspects of the family environment that differentiate families on the basis of how often they eat together, and it's the first to use a fixed-effects approach that focuses on how changes in family dinners relate to changes in adolescent outcomes. Estimates are based on a sample of about 18,000 children from the National Longitudinal Survey of Adolescent Health.

"Meals may afford a regular and positive context for parents to connect with children emotionally, to monitor their social and academic activities, and to convey values and expectations. This is what we suspect is driving any causal relationship between family dinners and child well being. But, family dinners also appear to be part and parcel of a broader package of practices, routines, and rituals that reflect parenting beliefs and priorities, and it's unclear how well family dinners would work unbundled from the rest of that package," said Musick.

The authors add that future work needs to go further in assessing which elements of mealtime may be most salient, looking beyond how often families eat together to examine whether talking, television, texting, eating the same food, or helping in the kitchen mediate or moderate the potential benefits of mealtime.

f you are a white girl, a black girl or a black boy, exposure to today's electronic media in the long run tends to make you feel worse about yourself. If you're a white boy, you'll feel better, according to a new study led by an Indiana University professor.

Nicole Martins, an assistant professor of telecommunications in the IU College of Arts and Sciences, and Kristen Harrison, professor of communication studies at the University of Michigan, also found that black children in their study spent, on average, an extra 10 hours a week watching television.

"We can't deny the fact that media has an influence when they're spending most of their time — when they're not in school — with the television," Martins said.

Harrison added, "Children who are not doing other things besides watching television cannot help but compare themselves to what they see on the screen."

Their paper has been published in Communication Research. Martins and Harrison surveyed a group of about 400 black and white preadolescent students in communities in the Midwest over a yearlong period. Rather than look at the impact of particular shows or genres, they focused on the correlation between the time in front of the TV and the impact on their self-esteem.

"Regardless of what show you're watching, if you're a white male, things in life are pretty good for you," Martins said of characters on TV. "You tend to be in positions of power, you have prestigious occupations, high education, glamorous houses, a beautiful wife, with very little portrayals of how hard you worked to get there.

"If you are a girl or a woman, what you see is that women on television are not given a variety of roles," she added. "The roles that they see are pretty simplistic; they're almost always one-dimensional and focused on the success they have because of how they look, not what they do or what they think or how they got there.

"This sexualization of women presumably leads to this negative impact on girls."

With regard to black boys, they are often criminalized in many programs, shown as hoodlums and buffoons, and without much variety in the kinds of roles they occupy.

"Young black boys are getting the opposite message: that there is not lots of good things that you can aspire to," Martins said. "If we think about those kinds of messages, that's what's responsible for the impact.

"If we think just about the sheer amount of time they're spending, and not the messages, these kids are spending so much time with the media that they're not given a chance to explore other things they're good at, that could boost their self-esteem."

Martins said their study counters claims by producers that programs have been progressive in their depictions of under-represented populations. An earlier study co-authored by her and Harrison suggests that video games "are the worst offenders when it comes to representation of ethnicity and gender."

Other research is starting to show the impacts of other kinds of entertainment sources, such as video games and hand-held devices. It indicates that young people are becoming creative at "media multitasking."

"Even though these new technologies are becoming more available, kids still spend more time with TV than anything else," Martins said.

Interestingly, the young people were asked about their consumption of print media, but the results were not statistically significant.

Martins conducted the research while she was completing her Ph.D. at the University of Illinois, as part of a larger longitudinal study done with her co-author, Harrison. They sought out certain school districts in Illinois because of their diversity, but African-Americans were the predominant minority group.

Funding for this research came from the William T. Grant Foundation.