Affiliation: University of Education
- Differences in sleep and circadian preference between Eastern and Western German adolescentsChristoph Randler
Department of Biology, Pharmacy and Psychology, Institute of Biology I, University of Leipzig, Leipzig, Germany
Chronobiol Int 25:565-75. 2008..The finding of earlier rise and bed times of the East German pupils is consistent with the hypothesis that sunlight acts as the entrainment for the biological clock of adolescents, as sunrise is earlier in Eastern Germany...
- Association between morningness-eveningness and mental and physical health in adolescentsChristoph Randler
Institute of Natural Sciences and Technology, University of Education Heidelberg, Heidelberg, Germany
Psychol Health Med 16:29-38. 2011..These results indicate that eveningness might be an unspecific risk factor for mental and physical health...
- Ontogeny of morningness-eveningness across the adult human lifespanChristoph Randler
University of Education Heidelberg, Biology, Im Neuenheimer Feld 561 2, D 69120, Heidelberg, Germany
Naturwissenschaften 103:3. 2016..This meta-analytical approach shows that morningness-eveningness changes across the adult lifespan and that older age is related to higher morningness...
- Asymmetries in commitment in an avian communication networkChristoph Randler
Department of Biology, University of Education Heidelberg, Im Neuenheimer Feld 561 2, 69120, Heidelberg, Germany
Naturwissenschaften 100:199-203. 2013..The communication network is asymmetric. Some species invest more than they receive from other species. As mobbing might incur costs, these are unequally distributed across the community...
- Chronotype but not sleep length is related to salivary testosterone in young adult menChristoph Randler
University of Education Heidelberg, Im Neuenheimer Feld 561 2, 69120 Heidelberg, Germany
Psychoneuroendocrinology 37:1740-4. 2012..Sleep duration was uncorrelated with testosterone, suggesting that timing of sleep - rather than sleep length itself - is influenced by testosterone...
- Assortative mating in morningness-eveningnessChristoph Randler
University of Education Heidelberg, Germany
Int J Psychol 46:91-6. 2011..Therefore, two extreme chronotypes are unlikely to meet each other because they have the smallest overlap in their preferred active time during the day due to the circadian rhythmicity...
- Age and gender differences in morningness-eveningness during adolescenceChristoph Randler
University of Education Heidelberg, Department of Natural Sciences, Heidelberg, Germany
J Genet Psychol 172:302-8. 2011..Composite Scale of Morningness scores are related to puberty scores in boys and girls, and when combining data (i.e., higher pubertal development was related to eveningness)...
- Foot preferences in wild-living ring-necked parakeets (Psittacula krameri, Psittacidae)Christoph Randler
University of Education Heidelberg, Germany
Laterality 16:201-6. 2011..At the feeding location, 24 individuals were left-footed and 11 were right-footed. These observations suggest a foot preference in the ring-necked parakeet both on the population level and on the individual level...
- Morningness-eveningness, habitual sleep-wake variables and cortisol levelChristoph Randler
University of Education Heidelberg, Im Neuenheimer Feld 561, Heidelberg, Germany
Biol Psychol 85:14-8. 2010..When comparing extreme chronotypes, morning types had higher cortisol levels immediately after awakening than evening types. These results strongly suggest an association between morningness-eveningness and CAR...
- Associations among sleep, chronotype, parental monitoring, and pubertal development among German adolescentsChristoph Randler
University of Education Heidelberg, Im Neuenheimer Feld 561 2 D 69120, Heidelberg, Germany
J Psychol 143:509-20. 2009....
- In sync with the family: children and partners influence the sleep-wake circadian rhythm and social habits of womenCatherine Leonhard
University of Education Heidelberg, Heidelberg, Germany
Chronobiol Int 26:510-25. 2009..This study suggests children have a strong influence on their mother's lifestyle and sleep-wake rhythm, far beyond the first months of life, and that children are a more important social factor than the male partner...
- Morningness-eveningness comparison in adolescents from different countries around the worldChristoph Randler
Department of Biology, Pharmacy, and Psychology, University of Leipzig, Leipzig, Germany
Chronobiol Int 25:1017-28. 2008..Adolescents were found to be more morning oriented both toward the East and North. The results indicate that climate, longitude, and latitude contribute to chronotype...
- Smartphone addiction proneness in relation to sleep and morningness-eveningness in German adolescentsChristoph Randler
1 Institute of Science, Geography and Technology, University of Education Heidelberg, Heidelberg, Germany
J Behav Addict 5:465-73. 2016..According to the t-test results, girls had higher scores than boys in smartphone addiction. Conclusion Evening types and girls are more prone to become smartphone addicted. ..
- Outdoor light at night (LAN) is correlated with eveningness in adolescentsChristian Vollmer
Department of Biology, University of Education Heidelberg, Germany
Chronobiol Int 29:502-8. 2012....
- Further evidence for the influence of photoperiod at birth on chronotype in a sample of German adolescentsChristian Vollmer
Department of Biology, University of Education Heidelberg, Im Neuenheimer Feld 561 2, Heidelberg, Germany
Chronobiol Int 29:1345-51. 2012..Future studies may require larger sample sizes, may need to explore how neonatal light exposure modulates chronotype, and may need to track how puberty and adolescent lifestyle habits mask the photoperiod effect...
- The role of chronotype, gender, test anxiety, and conscientiousness in academic achievement of high school studentsArash Rahafar
a Department of Biology, University of Education Heidelberg, Heidelberg, Germany
Chronobiol Int 33:1-9. 2016..Future studies are needed to explore how gender and chronotype act together in a longitudinal panel design and how chronotype is mediated by conscientiousness in the prediction of academic achievement...
- Daytime sleepiness during transition into daylight saving time in adolescents: Are owls higher at risk?Anne Marie Schneider
University of Education, Heidelberg, Germany
Sleep Med 10:1047-50. 2009..Here, we looked at the transition into daylight saving time (DST) in adolescents. As adolescents tend to be evening types, one may expect that they suffer from a transition into DST...
- Evening types among german university students score higher on sense of humor after controlling for big five personality factorsChristoph Randler
Department of Life Sciences, Pharmacy and Psychology, University of Leipzig, Germany
Psychol Rep 103:361-70. 2008..Eveningness was related to sense of Humor scores in women but not in men. Social but not cognitive humor was predicted by eveningness...
- Association between chronotype and the constructs of the Three-Factor-Eating-QuestionnaireEva Schubert
University of Leipzig, Institute of Biology, Johannisallee 21 23, Leipzig, Germany
Appetite 51:501-5. 2008..No association was found between BMI and cognitive restraint, hunger and flexible control. Also, no relationships existed between sleep length on weekdays or on weekends and BMI or eating...
- Morningness-eveningness and amplitude - development and validation of an improved composite scale to measure circadian preference and stability (MESSi)Christoph Randler
a Institute of Natural Sciences, Geography and Technology, University of Education Heidelberg, Heidelberg, Germany
Chronobiol Int 33:832-48. 2016..Thus, this newly developed questionnaire contains three distinct dimensions. To reflect the new content, the scale is labelled morningness-eveningness-stability-scale improved (MESSi). ..
- Association between chronotype and diet in adolescents based on food logsDaniel Fleig
University of Education Heidelberg, Im Neuenheimer Feld 561 2, Heidelberg D 69120, Germany
Eat Behav 10:115-8. 2009..Mean breakfast time at the weekend was later in late chronotypes which was a result of later rise times of late chronotypes. The study showed that morning oriented pupils exhibit a healthier and more regular lifestyle...
- Morningness-eveningness in a large sample of German adolescents and adultsChristoph Randler
University of Tuebingen, Department of Biology, Auf der Morgenstelle 24, D 72076 Tubingen, Germany
Heliyon 2:e00200. 2016....
- Latitude affects Morningness-Eveningness: evidence for the environment hypothesis based on a systematic reviewChristoph Randler
University of Tubingen, Department of Biology, Auf der Morgenstelle 24, D 70726 Tubingen, Germany
Sci Rep 7:39976. 2017..The full model showed an influence of age and of sunset on CSM scores, but not of photoperiod and average temperature. Sunset, therefore, seems to be the most important statistical predictor for the observed latitudinal gradient...