Morningness & Eveningness
By Gabija Kiburtaitė
Psbns09-2
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.
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.
Chronotypes
Two opposite chronotypes
exist:
• Morningness;
• Eveningness.
Most people lie somewhere
in between.
People who share a
chronotype have similar
activity-pattern timing.
Morning Type
Morning people wake up
early and are most alert in
the first part of the day.
Also called larks, earlyrisers or A-persons.
Mood declines over day.
Energetic in the mornings,
out of steam in the
evenings.
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.
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.
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.
Prevalence
One study:
•80% morning people,
•17% evening people,
•3% afternoon people.
Another survey:
•15% morning people,
•25% evening people,
•60% intermediates.
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.
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.
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.
References


http://en.wikipedia.org/
C. Wilson (Journal of Sleep and Sleep Disorders Research) “Early to bed, early to rise?”
(22/07/1998).
 Morningness-Eveningness.
 K. Wren “Science: Neuroscientists Probe the Differences Between Early and Late Risers”
(23/04/2009).
 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).
 “Are You a Lark or an Owl?” (05/2009).
 M. Smolensky, L. Lamberg “Are You a Lark, an Owl, or a Hummingbird?”.
 M. Giampietro , G.M. Cavallera “Morning and evening types and creative thinking” (2007).
Pictures:
 http://softwareengineering.vazexqi.com/files/statistics.jpg
 http://www.jamielatendresse.com/stuff/Chronotype_Helv_1-sml.jpg
 https://vr6kqg.blu.livefilestore.com/y1mj5GIIfCa8NJNGOjvgU6ty9y3vaMaH8c8-5T9DIvT_U9UpCpRp04josWPuR63mGhZPARjY4tw9PVoGbDGiC6ManYZVe8tQBXARPOKseeq7Mi8RpJrlQgN1qxE6QXAWsFutyAScWn8P_P68gT7fHQ/daynight.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://rlv.zcache.com/meadow_lark_photosculpture-p153708254934966605u30k_400.jpg
 http://images41.fotki.com/v1243/photos/2/292835/2766713/night_owl_sticker5-vi.jpg
 http://www.stacken.kth.se/~foo/weekpics/nightowl.jpg
Do You have any questions?