1. Morningness & Eveningness By Gabija Kiburtaitė Psbns09-2

2. Circadian rhythms  It is a roughly 25-hour cycle of the biochemical, physiological or behavioral processes.  Measured by melatonin secretion and core body temperature.  Humans are normally diurnal animals.

4. What chronotype is?  Chronotype (also called circadian type, diurnal preference or diurnal variation) is an attribute of humans reflecting whether they are alert early or late in the day.  Chronotype is largely independent of ethnicity, gender, and socioeconomic position.  The age affects chronotype.

5. Chronotypes  Two opposite chronotypes exist: Morningness; Eveningness.  Most people lie somewhere in between.  People who share a chronotype have similar activity-pattern timing.

6. Morning Type  Morning people wake up early and are most alert in the first part of the day.  Also called larks, early- risers or A-persons.  Mood declines over day.  Energetic in the mornings, out of steam in the evenings.

7. About Morning People  Morning people fall asleep faster.  They have a higher daytime temperature with an earlier peak time.  The daily body temperature minimum occurs at about 4am for morning people.  Students who are morning people get better grades in college.

8. Evening Type  Evening people are most alert in the late evening hours and prefer to go to bed late.  Also called night owls, late-risers or B-persons.  Mood rises over day.  Sleepy in the mornings, energetic in the evenings.

9. About Evening People  Owls have more variable bedtimes than larks.  The daily body temperature minimum occurs at about 6am for evening people.  Evening people are more alert after 10.5 hour without sleep than morning people.

10. Prevalence  One study: 80% morning people, 17% evening people, 3% afternoon people.  Another survey: 15% morning people, 25% evening people, 60% intermediates.

11. Personality Differences  In the Big Five personality model morningness correlates positively with Agreeableness trait, slightly negatively correlates with Neuroticism trait and slightly positively correlates with Conscientiousness trait.  Pre-teen kids who were more active in the evenings are likely to experience more behavioral issues during adolescence.  Evening people get higher scores for components of creative thinking such as fluidity, flexibility and originality.

12. Causes  The reason why people have different chronotypes seems to be genetic.  Researchers studied the CLOCK gene.  They found that subjects with a specific variation of CLOCK gene were most likely evening people.

13. Conclusions  Chronotypes are related with biological factors.  Chronotype is most likely determined by genetic causes.  Morning and evening people have quite different timing in alertness.  There is some personality and cognitive differences among opposite chronotypes.

14. References  http://en.wikipedia.org/http://en.wikipedia.org/  C. Wilson (Journal of Sleep and Sleep Disorders Research) “Early to bed, early to rise?” (22/07/1998).Early to bed, early to rise?  Morningness-Eveningness. Morningness-Eveningness  K. Wren “Science: Neuroscientists Probe the Differences Between Early and Late Risers” (23/04/2009).Science: Neuroscientists Probe the Differences Between Early and Late Risers  C. G. DeYoung. L. Hasher, M. Djikic, B. Criger, J. B. Peterson “Morning people are stable people: Circadian rhythm and the higher-order factors of the Big Five” (30/01/2007).  Night Writer “Sleep Discrimination” (1997).Sleep Discrimination  “Are You a Lark or an Owl?” (05/2009).Are You a Lark or an Owl  M. Smolensky, L. Lamberg “Are You a Lark, an Owl, or a Hummingbird?”.Are You a Lark, an Owl, or a Hummingbird?  M. Giampietro, G.M. Cavallera “Morning and evening types and creative thinking” (2007).Morning and evening types and creative thinking Pictures:  http://softwareengineering.vazexqi.com/files/statistics.jpg http://softwareengineering.vazexqi.com/files/statistics.jpg  http://www.jamielatendresse.com/stuff/Chronotype_Helv_1-sml.jpg http://www.jamielatendresse.com/stuff/Chronotype_Helv_1-sml.jpg  https://vr6kqg.blu.livefilestore.com/y1mj5GIIfCa8NJNGOjvgU6ty9y3vaMaH8c8-5- T9DIvT_U9UpCpRp04josWPuR63mGhZPARjY4tw9PVo- GbDGiC6ManYZVe8tQBXARPOKseeq7Mi8RpJrlQgN1qxE6QXAWsFuty- AScWn8P_P68gT7fHQ/daynight.jpg https://vr6kqg.blu.livefilestore.com/y1mj5GIIfCa8NJNGOjvgU6ty9y3vaMaH8c8-5- T9DIvT_U9UpCpRp04josWPuR63mGhZPARjY4tw9PVo- GbDGiC6ManYZVe8tQBXARPOKseeq7Mi8RpJrlQgN1qxE6QXAWsFuty- AScWn8P_P68gT7fHQ/daynight.jpg  http://www-tc.pbs.org/wgbh/nova/sciencenow/3214/images/01-coll-dna-knoll-l.jpg http://www-tc.pbs.org/wgbh/nova/sciencenow/3214/images/01-coll-dna-knoll-l.jpg  http://warkscol.files.wordpress.com/2009/11/thb93559.jpg http://warkscol.files.wordpress.com/2009/11/thb93559.jpg  http://rlv.zcache.com/meadow_lark_photosculpture-p153708254934966605u30k_400.jpg http://rlv.zcache.com/meadow_lark_photosculpture-p153708254934966605u30k_400.jpg  http://images41.fotki.com/v1243/photos/2/292835/2766713/night_owl_sticker5-vi.jpg http://images41.fotki.com/v1243/photos/2/292835/2766713/night_owl_sticker5-vi.jpg  http://www.stacken.kth.se/~foo/weekpics/nightowl.jpg http://www.stacken.kth.se/~foo/weekpics/nightowl.jpg

15. Do You have any questions?