Scientific studies

Here you find an overview about scientific studies and publications on important educational questions

Waldorf school
Play and its importance
Age of school enrolment
Emotional and social education
Electronic media: Health, school achievement, violence (tv / computer games), computer addiction.

See also >> Research Institute for Waldorf Education (USA) and >> Waldorf Researches and Educators Network (international).

Waldorf School

Waldorf Schools in comparision

Dahlin, Bo (2007): The Waldorf School - Cultivating Humanity? A report from an evalulation of Waldorf schools in Sweden. Karlstad University Studies 2007:29. (PDF, 102 p.).

Oberman, Ida (2007): Learning from Rudolf Steiner: The relevance of Waldorf Education for urban public school reform. USA. (PDF, 38 p.).

Woods, Philip et al. (2005): Steiner Schools in England. University of West of England, Bristol / Department for Education and Skills, Research Report No 645. (PDF, 208 p.).

Gidley, Jennifer (2008): Turning Tides: Creating Dialogue between Rudolf Steiner and 21st Century Academic Discourses. A Brief Report on Steinerbased Academic Research in Australia in Context. [>> Project Report, 6 p. / Project Data, 28 p. / Bibliography, 7 p.].

Wallner-Paschon, Christina (2009): Kompetenzen und individuelle Merkmale der Waldorfschüler/innen im Vergleich. in: Schreiner, Claudia / Schwantner, Ursula (Hg.): PISA 2006. Österreichischer Expertenbericht zum Naturwissenschafts-Schwerpunkt. Leykam Buchverlagsgesellschaft.

Studies about former Waldorf students

Barz, Heiner / Randoll, Dirk (2007): Absolventen von Waldorfschulen. VS Verlag für Sozialwissenschaften (393 p., 33 €). [>> Summary / Questions (German) /  Raw Data (496 p., German)]

Randoll, Dirk / Barz, Heiner (Hg.) (2007): Bildung und Lebensgestaltung ehemaliger Schülerinnen und Schüler von Rudolf Steiner Schulen in der Schweiz. Peter Lang Verlag. (>> German short version)

Mitchell, David / Gerwin, Douglas (2007): Survey of Waldorf Graduates, Phase II. Research Institute for Waldorf Edcuation, Wilton/USA. (171 p.). O [>> Summary (Power Point, 55 p.) / Abstracts (10 S.)]

Mitchell, David / Gerwin, Douglas (Hg.) (2008): Survey of Waldorf Graduates, Phase III. Research Institute for Waldorf Edcuation, Wilton/USA / PFB (122 p., 30€). O 

Dahlin, Bo (2005): A summary of the Swedish Waldorf School Evaluation Project. (15 p.).

Hansen, Troels (2003): Where did they go? (PDF, 28 p.). [Analysis of about 600 former Waldorf students in Denmark]

Ribeiro, Wanda / de Jesus Pereira, Juan Pablo (2007): Seven myths about the social participation of Waldorf graduates. (PDF, 17 p.). [Analysis of 108 former Waldorf students in Sao Paulo, Brazil].

Play and its significance

Einsiedler W et al. (1985): Phantasiespiel 3- bis 6-jähriger Kinder in Abhängigkeit von der Spielzeugstruktur. In: Zeitschrift für Entwicklungspsychologie u. Pädagogische Psychologie 17, 242-257. [2]

Ginsburg K et al. (2007): The Importance of Play in Promoting Healthy Child Development and Maintaining Strong Parent-Child Bonds. Pediatrics, 119, 1/2007, S. 182-191. [Website]

Miller, E / Almon, J: Crisis in the kindergarten. Why children need to play at school. Alliance for Childhood, 2009 (72 p., PDF). [Summary, 8 p.]

Olfman S (Hg.) (2003): All Work and no Play. How Educational Reforms are Harming our Preschoolers. Westport/London 2003. [2]
- including: D.G. Singer et al.: A Role of Play in the Preschool Curriculum. S. 43-65.
> Survey of the literature showing that children who play a lot increasingly show complex thinking structures, and develop social and other basic competences.
- including: J. Almon: The Vital Role of Play in Early Childhood Education.

Singer DG et al. (2008): Children’s Pastimes and Play in Sixteen Nations: Is Free-Play Declining? American Journal of Play, Vol. 1, No. 3 (Winter 2008). [>> Abstracts]

Scott WB (2002): Systems Strategy Needed To Build Next Aero Workforce. In: Aviation Week and Space Technology, 6. Mai 2002, 61-62. [2]
> An expert in the American space industry calls for more literacy and free play as the basis for creativity and powers of imagination.

Wilson FR (1998): The Hand: How Its Use Shapes the Brain, Language, and Human Culture. New York 1998. [2]
> A neurologist at Standford University shows the importance of hand activities on mental development, based on cultural and evolutionary analysis.

Articles

Olfman S (2003): The Push for Early Childhood Literacy: A Risk Factor in Child Psychopathology (PDF 6 p.).

Clouder C (2003): The Push for Early Childhood Literacy:  A View from Europe (PDF 10 p.).

Enrolment age

Puhani PA, Weber AM (2006): Does the Early Bird Catch the Worm? Instrumental Variable Estimates of Educational Effects of Age of School Entry in Germany. Universität Hannover.

Shaw P et al. (2006): Intellectual ability and cortical development in children and adolescents. Nature 440, 676-679. [2]
> Children with relatively slow pace of development in the pre-school and primary school age later show a more significantly thicker neocortex in the bain and significantly higher achievements.

March C (2005): Academic redshirting: Does withholding a child from school entrance for one year increase academic success. Issues In Educational Research, Vol 15. [2]
> No significant differences; survey of two further studies.

Mühlenweg A / Puhani P (2010): The Evolution of the School Entry Age Effect in a School Tracking System. Journal of Human
Resources. [> Summary of Zentrum für Europäische Wirtschaftsforschung].
> School enrolment in the age of exact 6 years will lower the probability of going to a Gymnasium after class 4 with one-third. [Study with pupils of classes 5-13, who have been enrolled 1993-98 in Hessen/Germany].

Uphoff JK / Gilmore J (1985): Pupil Age at School Entrance - How Many Are Ready for Success? Educational Leadership 43, 86-90. [2]
> Children sent to school at a younger age more frequently have to repeat a school year.

The Scotsman, 30.6.2007: Children should start school a year later.
> An educational commission in Glasgow recommended the city authorities that children should be sent to school at the  age of 6 instead of 5 yeras old.

Emotional and social education

Clouder, Christopher (Hg.): Social and emotional education. An international analysis. Fundación Marcelino Botin Report 2008. (>> Abstracts).
- Preface (S. 7-17, PDF, 6 S. / >> Abstracts).
- Clouder, Christopher: Introducing Social and Emotional Education. (S. 21-44, PDF, 13 S. / >> Abstracts).
- World Situation (here also abstracts of the following chapters)
- Clouder, Christopher / Heys, Belinda: Aspects of Social and Emotional Learning in the United Kingdom. (S. 42-82, PDF, 21 S.).
- Dahlin, Bo: Social and Emotional Education in Sweden: Two Examples of Good Practice. (S. 83-116, PDF, 18 S.).
- Diekstra, René F.W.: Social and Emotional Education, or Skills for Life, in the Netherlands: a Review of History, Policies and Practices. (S. 117-149, PDF, 18 S.).
- Fernández-Berrocal, Pablo: Social and Emotional Education in Spain. (S. 150-187, PDF, 20 S.).
- Lantieri, Linda: Social and Emotional Learning as a Basis of a New Vision of Education in the United States. (S. 188-224, PDF, 19 S.).
- Paschen, Harm: Perspectives on Social and Emotional Education in Germany. (S. 225-252, PDF, 15 S.).
- Diekstra, René F.W.: Effectiveness of School-Based Social and Emotional Education Programmes Worldwide. (S. 253-315, PDF, 34 S. / >> Abstracts).

Various

Alexander R (ed.) (2009): Children, their World, their Education: final report and recommendations of the Cambridge Primary Review. Routledge, 2009 (608 p., 58 $, 31 £). O o o [Website | Booklet 42S. | Leaflet 6S. | Key conclusions 4S. | Press release 3p.]
> Very detailed study of the University of Cambridge about the question of „good education“, many suggestions for politicians.

Important results from biorhythm and brain research (World Teacher Conference 2008 in Dornach, Dr. Cysarz, Prof. Moser, Prof. Rittelmeyer, G. Haffelder).

Weikart, DP / Bond JT / McNeil JT (1978): The Ypsilanti Perry Preschool Project: Preschool years and longitudinal results through fourth grade. Monograph of the High/Scope Educational Research Foundation, 3. High/Scope Press, Ypsilanti, MI.
> Preschool education with focus on self-directed learning had enormous, positive effects on the biography. [> Wikipedia]

Electronic media

The wealth of academic studies is grouped under the following categories:

- Media Use and Computer Addiction
- Media and health
- Media and school achievement
- Television and violence
- Computer games and violence

The sources are noted in square brackets and listed at the very end.

Media Use and Computer Addiction

BITKOM (2009): Studie zur Mediennutzung: Schon Grundschüler häufig online. Pressemitteilung des Bundesverbandes Informationswirtschaft, Telekommunikation und neue Medien e.V. [PDF 2p.]
> Phone survey (n=1000): An existing internet access in German housholds is used in different ages as follows: 4-6 years 21%, 7-10 years 71%, 11-14 years 93%, 15-17 years 99%. - 90% of the teens (10-17 years) use messaging services a.o., 50% are uploading own pictures, 25% participate in discussion forums.

Rehbein F et al. (2009): Computerspielabhängigkeit im Kindes- und Jugendalter. Kriminologisches Forschungsinstitut Niedersachsen, Forschungsbericht Nr. 108 (PDF, 53 S.).
> Survey of 44.610 9th-graders. 4,3% of the girls and 16% of the boys are playing more than 4,5 hours per day. On average boys are playing 130min per school day and 167min per weekend day (2005: 91 and 140min). The biggest potential of addiction has the game "World of Warcraft".

Wölfling K et al. (2008): Computerspielsucht: Ein psychopathologischer Symptomkomplex im Jugendalter. Psychiatrische Praxis 2008; 35 (5): S. 226-232.
> Survey on 221 class 8 pupils in Berlin: 65% regularly play computer games, 10% of them show a psychopathological addiction. (in total 6,3% – 79% of them learn at a Hauptschule, 14% at a Realschule, 7% at a Gymnasium). The addicts are playing in the middle 5 hours a day, their achievment in school gets worse, they are loosing social contacts, suffer from nervousness, disquietness and a shifted wake-sleep cycle.

Media and health

Anshel J (1997): Computer Vision Syndrome: Causes and Cures. Ergonomic News 2, 18-19. [2]
> In the USA 30% children suffer headaches, dry eyes and light hypersensitivity through long exposure to electronic screens.

Dietz WH, Gortmaker SL (1985): Do we fatten our children at the television set? Obesity and television viewing in children and adolescents. Pediatrics 75, 807-812. [1,20]
> Data from 6,000 overweight children and youth showed a clear and temporal correlation between television and being overweight.

Johnson JG et al. (2004): Association Between Television Viewing and Sleep Problems During Adolescence and Early Adulthood. Arch Pediatr Adolesc Med 158, 562-568. [2]
> Those who watch TV for 3 hours or more daily has a significantly higher risk of sleeplessness by the age of 22.

Morgenstern M et al. (2009): Jugendliche und Alkoholwerbung. Einfluss der Werbung auf Einstellung und Verhalten. DAK Forschung (PDF 18S.). [>> Pressemappe]
> Study with 3.415 girls and boys (10-17 years). From those young people who already had seen several of the shown TV spots more than 10 times, more than 90% already had drunken alcohol - and less than 20% from those who haven´t seen any alcohol advertising spots (1,5%).

Gortmaker SL et al. (1996): Television viewing as a cause of increasing obesity among children in the United States, 1986-1990. Arch Pediatr Adolesc Med 150, 356-362. [1,23]
> Children under two yeras old who watch less than 2 (over 3) hours of television a day were initially 12% (28%) overweight; within the period of observation this increased a further 5% (19%). The causal relationship was clear.

Kalies H. et al. (2001): Übergewicht bei Vorschulkindern. Kinderärztliche Praxis 4, 227-234. [1,25]
> German pre-school children who daily watch 2 hours of television screens have a 70% higher chance of being overweight.

Ludwig DS, Gortmaker SL (2004): Programming obesity in childhood. The Lancet 364, 226-227. [1,22]
> Survey of over 50 studies that prove the relationship between television viewing and being overweight. Two of these studies from China showed no difference in 1997 but a clear difference by 2000.

Primack BA et al. (2009): Association between media use in adolescence and depression in young adulthood. Arch Gen Psychiatry 66(2), 181-188.
> Television exposure is associated with increased odds of depressive symptoms in young adulthood, especially in young men.

Wong ND et al. (1992): Television viewing and pediatric hypercholesterolemia. Pediatrics 90, 75-79. [1,28]
> A study of 1,081 young people aged from 2 to 20 years old showed the relative risk of higher cholesterol levels with an inherited tendency to fat metabolism irregularities of 1.6 (60%), against 2-4 hours of television consumption which already shows 2.2 (twice as high)  and over 4 hours already 4.8 times (almost five times higher).

Media and school achievement

Christakis DA et al. (2004): Early television exposure and subsequent attentional problems in children. Pediatrics 113, 708-713. [1,88]
> Attention deficit syndrome in seven-year-old children occurs more frequently when they have watched TV regularly from the age of 3 onwards. (Study carried out by University of Washington on 2,623 children).

Christakis DA (2009): The effects of infant media usage: what do we know and what should we learn? Acta Paediatrica 98, 8-16.
> Review of 78 studies of the last 25 years. Several results, e.g. increased probability of delayed and less language and other skills. - 90% of all children under two years watch TV regularly. In a survey in the USA 29% of parents thought, TV would be "good for the brains".

Clotfelter CC et al. (2008): Scaling the digital divide: home computer technology and student achievement. Duke University, 29.7.2008 (PDF, 26S.).
> Students who have access to home computers and internet achieve significant lower scores in reading and math assessments.

Ennemoser M (2003): Effekte des Fernsehens im Vor- und Grundschulalter. Ursachen, Wirkungen und differenzielle Effekte. Nervenheilkunde 22, 443-453. [1,135]
> A careful five year study using diaries with 332 children from the last year in kindergarten to the second grade. In the grade three reading test children who watched less than 15 minutes televison daily scored over 1000 points, children with up to 2 hours television scored under 80 points. The effect was particularly strong in children from higher social  classes who watched 2 hours and among those from lower social classes who watched little television. In the vocabulary test children with a low IQ and high levels of television scored drastically lower point levels. (half as many as all others).

Fuchs Th, Wößmann, L (2004): Computers and student learning: bivariate and multivariate evidence on the availability and use of computers at home and at school. Brussels Economic Review 47 (3/4), 359-385. [2]
> PISA-data showing the negative effects of regular computer use on school achievement.

Hancox RJ, Milne BJ, Poulton R (2004): Association between child and adolescent television viewing and adult health: a longitudinal birth cohort study. Lancet 364, 257-262. [1,29]
> A long-term study with around 1000 people in New Zealand to observe the influence of socio-economic staus and IQ: 40% (10%) of those under 5 years old who watched TV less than 1 hour (over 3 hours) per day had a university qualification at the age of 26 and 15% (40%, of which 25% left school early) keine berufliche Qualifikation. had no professional qualification. 45% (27%) of the adults who daily watched 2-3 hours (<1 hour) a day of television between the age of 5 and 15 years old were overweight, which was similar to the smokers.

Jungwirth RJ, Ernst E, Pöhler H (2005): Fernsehkonsum beeinflusst die Sprachentwicklung von Vorschulkinder. Monatsschrift Kinderheilkunde 153, 386-387. [2]
> Television consumption influences language development in pre-school children.

Karten YJG et al. (2005): Stress in early life inhibits neurogenesis in adulthood. Trends in Neurosciences 28, 171-172. [2]

Kriminologisches Forschungsinstitut Niedersachsen (2006): Mediennutzung im Alltag von Kindern und Jugendlichen – Ausmaß, Inhalte und Zusammenhänge mit schulischem Erfolg. Ergebnisse der Schülerbefragung 2005. [2]
> Study on grade 4 children: Possessing a play console or television in their own rooms corresponds with significant more negative achievments in school.

Myrtek M (2003): Fernsehkonsum bei Schülern: ambulante psychophysiologische Untersuchungen im Alltag. Nervenheilkunde 22, 454-458. [1,123]
> Television viewing leads to lower achievement in school.

Myrtek M, Scharff C (2000): Fernsehen, Schule und Verhalten. Untersuchungen zur emotionalen Beanspruchung von Schülern. Huber, Bern. [1,125]
> Television tends to make individuals social outsiders. A study of 100 children from the age of 11 to 15 examined their pulse, heart frequency, subjective feelings and activity. A 15 year old with high (low) television viewing times spent 42% (35%) of the day alone, 12% (20%) with friends, 9% (15%) in conversation, 8% (13%) walking around, 1.3% (4.4%) practicing a musical instrument. In 11 year olds the effects were weaker but still highly significant

Spitzer M (2007): "Kinder lernen besser ohne Computer". Der Tagesspiegel, 22.6.2007.

Winterstein P, Jungwirth RJ (2006): Medienkonsum und Passivrauchen bei Vorschulkindern. Risikofaktoren für die kognitive Entwicklung? In: Der Kinder- und Jugendarzt 37, 205-211. [2]
> Pre-school children who have watched TV daily for three hours or more or have parents who smoke at home, show a reduced development based on their level of ability in drawing (Man-Drawing-Test).

Zimmerman FJ, Christakis DA (2005): Children´s Television Viewing and Cognitive Outcomes. A Longitudinal Analysis of National Data. In: Archives of Pediatrics & Adolescent Medicine 159, 619-625. [2]
> Children who watch a lot of television (> 3h/day) until the age of three statistically show significantly reduced speech and other cognitive abilities by the age of 6/7.

Televison and violence

In what follows the link is often made between the strength of effect of violence on the screen and real violence. This is 0.3, almost as high as the link between smoking and lung cancer. As a comparison: nicitine plaster/giving up smoking is 0.13. Many medicines e.g. for high blood pressure, high blood fat or high blood sugar lie significantly below this level but are prescribed despite the proven significant effect. [1]

American Academy of Pediatrics et al. (2000): Joint Statement on the Impact of Entertainment Violence on Children. Congressional Public Health Summit, 26. July 2000. [2]

Barry AMS (1997): Visual Intelligence: Perception, Image, and Manipulation in Visual Communication. State University of New York Press, Albany. [1,161]
> An average student in the USA after 12 years at school has spent about 13,000 hours at school and 25,000 hours in front of the TV. Children who grew up with cable TV or a video recorder have seen around 32,000 murders and 40,000 attempted murders by the time they are 18 and in certain ethnic groups in inner cities this total is higher. (Other studies show that in three out of four cases teh criminal gets away with it and in less than 5% of the cases a non violent solution is found).

Centerwall BS (1989): Exposure to television as a risk factor for violence. American Journal of Epidemiology 129, 643-652. [1,203]
> Comparison between white populations in the USA, Canada and South Africa: following the introduction of television in the US and Canada (in the 50s) the number of murders doubled within 10 to 15 years, in South Africa during the same period the total fell by 7%. Following the introduction of TV to South Africa (1975) the number of murder went up 130% by 1987.

Eron LD, Huesman LR (1986): The role of television in the development of prosocial and antisocial behavior. In: Olweus D et al. (Ed.): Development of antisocial and prosocial behaviour. Research, theories and issues. Academic Press, New York. 285-311. [1,173]
> Longitudinal studies (1960-81) on 875 boys: those who from the age of seven onwards grew up watching above average amounts of violence on TV was more likely to have come into conflict with the law by the age of 19 or to be violent towards women and children by the age of 30.

Hearold S (1986): A synthesis of 1043 effects of television social behaviour. Public Communication and Behavior 1, 65-133. [1,178]
> Metaanalysis of 230 studies involving about 100,000 subjects: strength of effect between violence in the media and aggressive behaviour was 0.30 in total – crime films 0.27, Westerns 0.35, comics 0.4, news 0.68, reality TV 0.7.

Johnson JG et al. (2002): Television viewing and aggressive behaviour during adolescence and adulthood. Science 295, 2468-2471. [1,195]
> Study involving 707 children in single child families: those who watched TV at the age of 14 was more violent between the age of 16 and 22. The effect was strongest amongst boys and among those who had previously be aggressive. The rate of violence by girls who watched a lot of TV (3 hours daily) was at the level of boys who watched little TV (1 hour daily). Boys who watch a lot of TV had a high effect (0.6) and it was even 0.5 for boys who watched only 1-3 hours daily. The study showed also the opposite effect: Violent behaviour leads to higher TV consumption.

Joy LA, Kimball MM, Zabrack MI (1986): Television and children´s aggressive behaviour. In: Williams TM (Ed.): The Impact of Television. Op. cit., 303-360. [1,169]
> In a Canadian community that first acquired TV in 1973 the level of verbal violence doubled in three years among boys and girls, physical violence rose three times, whilst in neighbouring communities which already had TV teh levels remained constant.

Lukesch H et al. (2004): Das Weltbild des Fernsehens: eine Untersuchung der Sendungsangebote öffentlich-rechtlicher und privater Sender in Deutschland. Roderer, Regensburg. [1,163]
Groebel J, Gleich U (1993): Gewaltprofil des deutschen Fernsehprogramms. Leske & Budrich, Opladen.
> At the beginning of the 1990s violence occured in 48% of all TV programmes. By 2002 that had risen to 79%. The proportion of severe and very severe acts of violence increased from 5 to 9 per hour. The percentage of violent programmes (that is to say the amount of time violence was being shown) increased by 6% in films and TV series to 94%; 10% in children’s programmes to 89% ( with a marked difference between the state and private channels of 5% and 14% respectively) and 78% in information and news programmes. Half of the violent events had no consequences or positive consequences. 

Paik H, Comstock G (1994): The effects of television violence on antisocial behavior: a metaanalysis. Communication Research 21, 516-546. [1,179]
> A meta-analysis of 217 studies bewteen 1957 and 1990 (overlapping with the study by Hearold by less than 50%) showed the strength of effect at 0,31. Using a somewhat different categorizing of the types of programmes, the results were: News, 0,25; crime/action thrillers, 0,3; cartoons 0,5. In the age groups: under 6 years, 0,4; followed by 6 to 11 years, 0,3; 18 to 21 years, 0,27, 12 to 17 years, 0,22, over 21 years, 0,18.

Robinson TN et al. (2001): Effects of reducing children´s television and video game use on aggressive behaviour: a randomized controlled trial. Arch Pediatr Adolesc Med 155, 17-23. [1,170]
> Reduction of electronic visial media in school children led to a significant reduction in cases of aggression reported by school children bewteen their peers and less verbal aggression in the playground.

Schmidtke A, Häfner H (1986): Die Vermittlung von Selbstmordmotiven und Selbstmordhandlung durch fiktive Modelle. Die Folgen der Fernsehserie „Tod eines Schülers“. Der Nervenarzt 57, 502-510. [1,158]
> Following the showing of the ZDF film „Death of a Pupil“ in Germany at the beginning of 1981 and the end of 1982 the number of railway suicides rose to 101 and 91 respectively, whilst the average in the years 1976-84 was 33. The total numbers of suicides in the age group 15 to 29 rose in the two months after the film from 0.45 to over 0.9 a day.

Walma van der Molen JAH et al. (2002): Television News and Fears: A Child Survey. Communications: The European Journal of Communications Research 27, 303-317. [2]
> 48% of 7 to 12 year old children react to TV news for adults with fear.

Computer games and violence

For the "strength of effect" see above under "Television and violence".

Anderson CA, Bushman BJ (2001): Effects of violent video games on aggressive behaviour, aggressive cognition, aggressive affect, physiological arousal, and prosocial behaviour: a meta-analytic review of the scientific literature. Psychological Science 12, 353-359. [1,224]
> Metaanalysis of 35 studies from 2000: computer and video games with aggressive contents increase the aggressive thoughts and lead to aggressive behaviour and reduced willingness to help others with a strength of effect of between 0.27 and 0.20

Anderson C, Gentile D, Buckley C: Video Game Effects on Children and Adults. Theory, Research and Public Policy. 2007.
> This book contains an overview of several studies that confirm the significant link bewteen violent video games and violent behaviour.

Baier D, Rabold S, Lüdders L, Pfeiffer C: Schülerbefragung 2005: Gewalterfahrungen, Schulschwänzen und Medienkonsum von Kindern und Jugendlichen. Kriminologisches Forschungsinstitut Niedersachsen, 2006.
> Paper about exeprience of violence, school absenteeism and media consumption among children and youth.

Bushman BJ, Anderson CA (2001): Media violence and the American public: scientific facts versus media misinformation. American Psychologist 56, 477-489. [1,278]
> The print media do not report the outcomes of scientific studies, on the contrary: since the 80s the effects of violence in the media increased, whilst reporting in the media tended to show much weaker results.

Funk JB et al. (2004): Violence exposure in real-life, video games, television, movies and the internet: is there desensitization? J Adolesc 27, 23-39. [1,238]
> A study on 150 10 year old school children showed a significant corellation between violent video games and a reduction of sensitivity to violence and its effects and to a reduced level of empathy.

Gentile DA, Anderson CA (2003): Violent video games: the newest media violence hazard. In: DA Gentile (Ed.): Media Violence and Children. Praeger, Westport, 131-152. [1,219]
> A study showing that the effects of violent video and computer games was greater the neuer they were.

Gentile, DA et al. (2004): The effects of violent video game habitus on adolescent hostility, aggressive behaviors, and school performance. J Adolesc 27, 5-22. [1,222]
> A study on 607 grade 8 and 9 youngsters. The percentage of physical violence involving pupils who didn’t watch violent videos to be between 4% and those who did by 38% in the peaceful quarter, in the agressive quarter the difference was 28% and 63%.

Koepp MJ et al. (1998): Evidence for striatal dopamine release durino a video game. Nature 393, 266-268. [1,216]
> A violent video caused a minimum of 100% increase in Dopamin production, a level seen only in patients taking amphetamines or psychopharmic medicines. Following experiences of success the hormone dopamin relaesed opium-like substances in the body and caused  positive emotions and play a central role in creating meaning and other learning processes. Thus violence is intensively learned.

Krahé B / Möller I (2004): Playing violent electronic games, hostile attributional style, and aggression-related norms in German adolescents. Journal of Adolescence, vol. 27, 53-69.
> Violent Computer games lead to increased aggressive behaviour and reduced empathy.

Krahé B / Möller I (2006): Aktuelle Forschungsprojekte zum Thema "Mediengewalt": Fragestellungen, Methode und Ergebnisse. Online-Dokument, 8 p.

Kraut R et al. (1998): Internet paradox. American Psychologist 53, 1017-1031. [1,228]
> Study of 169 internet users in 73 households after they had been online for two years: family members spoke less frequently with each other, their circle of friends became smaller and loneliness and depression increased.

Möller I / Krahé B (2009): Exposure to violent video games and aggression in German adolescents. Aggressive Behavior, 35, 75-89. [Abstracts]
> Study with 295 youngsters at an interval of 30 months: the ones who played more violent games showed at the end a greater tendence for aggression. The opposite relation (more aggression > more playing) has not been found.

Mori A, Iwadate M, Kita Y (2002): Influence of Computer Games on Occurrence Patterns of Brain Activity in the Human Prefrontal Cortex. Kongressbericht 2002 der Society for Neuroscience, Washington, D.C. [2]
> Regular playing of computer games reduces the activity of the brain areals that are associated with emotions and creative thought processes.

Pfeiffer C (2007): Offener Brief an den Bundestagsausschuß für Kultur und Medien zur Gefährlichkeit gewaltorientierter Computerspiele. Kriminologisches Forschungsinstitut Niedersachsen, 3.5.2007.
> One in two 10 year old children has experience with games that are restricted to those under 16 and one in five play them. Among 14/15 year olds the percentage  is 82%.

Sanders CE et al. (2000) : The relationship of internet use to depression and social isolation among adolescents. Adolescence 35, 237-242. [1,229]
> Study of 89 youths: the more internet usage the worse the relationship to parents and friends. Using 8 questions with a possible points total of 40 infrequent (frequent >2h) users assessed their relationships as follows: friends 31 (25), mother 28,5 (21,5), father 24,5 (23) and depressivity 23 (26).

Uhlmann E, Swanson J (2004) : Exposure to violent video games increases automatic aggressiveness. J Adolesc 27, 41-52. [1,236]
> Study with 121 18 year old psychology students: a ten minute violent game Doom led to significant changes in the unconscious associations, whilst conscious responses remained unchanged.

References/sources
[1] Manfred Spitzer: Vorsicht Bildschirm. Dtv, 2006.
[2] Christian Rittelmeyer: Kindheit in Bedrängnis. Kohlhammer, 2007. English: Childhood under threat (Fulltext as PDF).