DOCSLIB.ORG

MEDICAL CHALLENGES: EFFECTS of TRAVEL FATIGUE and JET LAG

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
MEDICAL CHALLENGES: EFFECTS of TRAVEL FATIGUE and JET LAG MEDICAL CHALLENGES: EFFECTS of TRAVEL FATIGUE and JET LAG Prof Christa Janse van Rensburg MBChB, MSc, MMed, MD FACSM, FFIMS Sports Medicine & SEMLI, University of Pretoria Consultant Rheumatologist, Eugene Marais Hospital South Africa IOC Advanced Team Physician Course TOKYO, 01-03 JULY 2019 INTRODUCTION @ChristaJVR #IOCATPC2019 No disclosures A) CIRCADIAN SYSTEM ~24h self-sustained variation in physical, mental & behavioural function • Functions endogenously: ✓autonomous ✓rhythm maintained in absence of external cues • Circadian timing: Master Clock: Suprachiasmatic nucleus (SCN) in HT Peripheral Clocks: in mostly every cell of all tissue REGULATION • Complex series of interlocking transcriptional feedback loops (clock genes that code for clock proteins) • Various stimuli = zeitgebers or "time givers” ✓ Light/dark cycle most NB advance or delay phase • Rhythmical change phase response curve (PRC) - Amount of phase shift depends on zeitgeber: - timing - intensity - duration - frequency - Synergistic or antagonistic action of zeitgebers i.e. interact in ‘push’ or ‘pull’ on circadian rhythm phase • Inter-individual variations - Chronotype differences (morning lark vs. night owl) The Nobel Prize in Physiology or Medicine 2017 - Genetic variances of circadian-related phenotypes was awarded jointly to Rosbash M, Young MW, Hall JC for their pioneering discovery that our [Period (PER1, PER2, PER3); Cryptochrome (CRY1,CRY2) circadian clocks are regulated by a small group genes] of genes working at individual cell level. CIRCADIAN RHYTHM DESYNCHRONISATION • Explained in one of 3 ways: ✓Temporary misalignment between external environment (@ destination time-zone) & timing of internal CR ✓Dysfunction of the circadian clock e.g. due to polymorphisms in human clock genes (PER3) ✓Dysfunction of the efferent and/or afferent pathways • Jet lag internal circadian system cannot keep up with rapid light/dark change adaptation to new environment • Entrainment of CR - Inputs from retina, melatonin receptors, brain (CNS arousal) - reset by exposure to external stimuli - bright light/darkness, melatonin, exercise, meal times, etc. B) TRAVEL ISSUES Travel Fatigue Jet Lag Motion sickness DVT Other TRAVEL FATIGUE & JET LAG Uncontrollable factors Controllable factors • Passenger next to you • Journey anxiety • Confined space • Nutrition • Length of flight • Hydration • Crossing time zones (extra 15-20ml for each hour in • flight) Altitude changes (poor air quality) • Time of sleep • Air pressure fluctuations • Body temperature • Stopovers /Delays • Movement / activity • Turbulence • Vibration /Noise Travel fatigue Jet lag Definition Temporary exhaustion, tiredness TemporaryBody`s daily disorder rhythms / outdesynchronosis of sync with * destination time zone Mechanism / Associated with any long journey Rapid long-distance, trans-meridian Cause (irrespective of mode of transport) travel Flight’s direction > length Direction of N S W E travel Seasonal change Shift in local time e.g. Depart from JHB at 30°C, disembark in e.g. Depart 10h00 from London, arrive 13h00 Frankfurt at 0°C in NY (watch indicating London time 18h00) W E = 8-hour flight across 5 time zones 2 time zones in any direction 3 time zones in directions E-W / W-E Travel fatigue Jet lag Duration • Subsides next day / after shower / • Lasts several days to weeks night’s sleep • Resolves with resynchronisation • Quicker overcome BUT can • 1 day/time zone accumulate over course of season • Can be persistent & impact athlete’s capacity to recover & perform Severity • Vast inter- & intra-individual variations • Frequency of trips & length of season play a role Travel Direction and Body Clock Eastward Westward Phase shift • Advance (!!only if <8 hrs time zone • Delay (up to 12 hrs time zone difference) BodyNB! clock cycle difference, otherwise same as westward) Travel: • Shorten 60 min/d (each day in new time • Extend 90 min/d (each day in new time • Direction zone) longer to adapt zone) shorter to adapt • Distance • Frequency • More difficult (easier for morning type • Easier for most travellers Season length person) Sleep pattern • Difficult to fall asleep • Sleepy early evening • Difficult to wake up • Wake up early C) POTENTIAL IMPLICATIONS Hypoxia Circadian rhythm disruption Improved performance (2-11%): ✓Neuromuscular function ✓VO2max ✓Grip strength ✓Peak force of big muscle groups Fatigue Mood Disrupted sleep Illness Injury D) HOW TO COPE? Management of: • Environmental challenges • Travel fatigue & Jet lag • Much effort, mainly to shift CR only partial success • Effects depend on internal circadian time of treatment Circadian phase determined by: ✓ Melatonin (plasma, salivary or urinary) ✓ Habitual sleep onset at home ✓ CBTmin Diet: Bright light: EAST - late evening delays - timing of meal xBiological night time - morning (after CBTmin) seems more NB WEST dvancesadvances than type of meal Low dose melatonin: Sleep: - very late evening to - pre-adapt by morning delays shifting schedule - mid-afternoon to bed-time towards time at advances destination - power naps Exercise: - avoid sleep debt - cannot reliably shift CR - may maintain arousal level - early morning exercise may delay - early evening exercise may advance Sunrise: TRAVEL SCENARIO 04:47am Sunset: South African Olympic Team travelling to the 18:47pm 2020 Summer Olympic Games in Tokyo Total daylight: 13:59hrs 24 July to 9 Aug Athletes: 138 Support staff: 60 Time zones crossed: 7 (W E) Hours difference: 7 Tokyo: 6am South Africa: 11pm Seasonal Change: (S N) PLANNING: Journey Melatonin & Cortisol Rhythms Diurnal Rhythms Sleep / Wake Rhythms Short stress of missing next flight, anxiety Flight choice Long fatigue, boredom, frustration ARRIVAL TIME FLIGHT HOME TIME TIME FROM TO LAY-OVER DESTINATION DURATION (SOUTH AFRICA) DIFFERENCE (TOKYO) Jhb Hong Kong 13 hrs 6 hrs 2 hrs 14.30 7.30 Hong Kong Tokyo Total4.30 flighthrs 7 hrs Jhb Singapore duration:10.30 hrs 6 hrs 2.40 hrs 17.35 10.35 Singapore Tokyo Approx.7 hrs 7 hrs Jhb Dubai 8.3018hrs hrs 2 hrs 1.50 hrs 15.55 8.55 Dubai Tokyo 10 hrs 7 hrs ✓ Eastward flight advance body clock ✓ Resynchronisation takes 1 day / time zone crossed Light exposure Light avoidance ✓ in the 6hrs after CBTmin ✓ in the 6hrs before CBTmin CBTmin ✓ 12h00 – 18h00 at destination ✓ 04h00 – 10h00 at destination ✓ sleep easiest @ low CBTmin ✓ approximately 3 – 6 am ✓ inter-individual difference CONCLUSION • Travel fatigue & jet lag potentially modifiable • Risk factors include: ✓ Physical fitness ✓ Time zones crossed ✓ Sleeping habits ✓ Age ✓ Flight direction ✓ Chronotype ✓ Previous experience ✓ Time at destination ✓ Sex • Many uncertainties on methods to advance or delay the body clock no cure yet (preserve sleep and alertness) • Environmental conditions need to receive attention • Illness preventative measures need to be in place • Meticulous planning! • Jet lag calculators: www.britishairways.com/travel/drsleep/public/en_gb www.jetlagrooster.com Correspondence: [email protected] Twitter: @ChristaJVR www.ioc-preventionconference.org/atpc2019/ CALL FOR ABSTRACTS & WORKSHOPS IS NOW OPEN Deadline: 15 September 2019 Submit your work on the website: www.ioc-preventionconference.org #IOCprev2020.
Load more

Recommended publications
  • The Effects of Time of Day and Chronotype on Cognitive and Physical Performance in Healthy Volunteers Facer-Childs, Elise; Boiling, Sophie; Balanos, George
    CORE Metadata, citation and similar papers at core.ac.uk Provided by University of Birmingham Research Portal The effects of time of day and chronotype on cognitive and physical performance in healthy volunteers Facer-Childs, Elise; Boiling, Sophie; Balanos, George DOI: 10.1186/s40798-018-0162-z License: Creative Commons: Attribution (CC BY) Document Version Publisher's PDF, also known as Version of record Citation for published version (Harvard): Facer-Childs, E, Boiling, S & Balanos, G 2018, 'The effects of time of day and chronotype on cognitive and physical performance in healthy volunteers', Sports Medicine - Open, vol. 4, no. 1, 47. https://doi.org/10.1186/s40798-018-0162-z Link to publication on Research at Birmingham portal Publisher Rights Statement: Checked for eligibility 09/11/2018 Sports Medicine - Open20184:47 https://doi.org/10.1186/s40798-018-0162-z General rights Unless a licence is specified above, all rights (including copyright and moral rights) in this document are retained by the authors and/or the copyright holders. The express permission of the copyright holder must be obtained for any use of this material other than for purposes permitted by law. •Users may freely distribute the URL that is used to identify this publication. •Users may download and/or print one copy of the publication from the University of Birmingham research portal for the purpose of private study or non-commercial research. •User may use extracts from the document in line with the concept of ‘fair dealing’ under the Copyright, Designs and Patents Act 1988 (?) •Users may not further distribute the material nor use it for the purposes of commercial gain.
    [Show full text]
  • INSOMNIA Authors: Dr
    INSOMNIA Authors: Dr. Ashna Bowry, Dr. Karl Iglar Created Dec 2010 Overview Insomnia is commonly reported due to daytime fatigue, physical discomfort and psychological distress1. Although highly prevalent and can lead to physical and mental health problems as well as social, occupational and economic repercussions, poor sleep quality is often overlooked. The prevalence of insomnia is estimated to be 13.4% in Canada and 6-10% worldwide. 2 Definitions Acute insomnia: new onset of difficulty initiating or maintaining sleep, with the presence of an identifiable trigger lasting < 4 wks. duration;Chronic insomnia: symptoms lasting >4 weeks; Primary insomnia: a conditioned state of hyperarousal that inhibits the sleep process. Not usually associated with a comorbidity and often lasts < 1 month; Secondary insomnia: associated with primary sleep disorders (C: Circadian rhythm, A: sleep apnea, L: restless legs), medications, medical or psychiatric conditions (mood disorders and substance abuse) – see table 1; Sleep-onset latency: the time it takes to fall asleep. Normal is < 30 minutes8 Diagnostic Considerations Consider diagnosis of insomnia for patients with difficulty falling asleep, staying asleep or non-refreshing sleep in a person who has the opportunity to sleep 7-8 hours per night. Clinically relevant if effects daytime functionality (daytime dysfunction, fatigue, poor concentration and irritability.) 1,3 Sleep history is essential and should include: recent life changes, alcohol/drug use, sleep and wakefulness patterns, effect on functioning.
    [Show full text]
  • Sleep Self-Care
    University of California, Berkeley 2222 Bancroft Way Berkeley, CA 94720 SLEEP SELF-CARE All of us have trouble sleeping from time to time. This is perfectly normal. Sleep problems (also known as insomnia) are often triggered by sudden life changes that lead to increased stress. For instance, following the death of a loved one, a car accident or a promotion to a new job, many people experience difficulties getting a good night’s sleep. This normal response to stress usually lasts for a short time, rarely longer than a week or two. However, some people have chronic problems sleeping which do not seem to go away. If you are one of these people, or you are having temporary insomnia, this Self-Care Guide should help. It will give you some general information about sleep, as well as provide a number of helpful suggestions to aid those with sleep problems. Read it carefully, as many common sleep problems are caused by one’s own habits, and by adopting some of the following sleep-promoting behaviors, most people can get a good night’s rest without the aid of drugs. Taking sleeping pills is not the answer! For people whose only complaint is I can’t sleep well or I can’t get to sleep easily, taking sleeping pills may do more harm than good. Most authorities recommend against the regular use of sedative drugs (like Valium, Dalmane, Librium and barbiturates) for the following reasons: ! Sedatives change nervous system activities during sleep; for example, they may reduce the normal periods of dreaming.
    [Show full text]
  • The Dark Side of the Night Owl Life
    somewhere between the two extremes and is The Dark Side of rather well-aligned with their activities. The discrepancy between biological the Night Owl Life rhythms and social timing that befalls larks and owls is known as social jetlag (SJL) Social jetlag causes “night owls” who follow (Wittman et al., 2006). For larks, who have “early bird” schedules to perform worse earlier bedtimes, this could mean having to academically. stay up later on weekends for social activities. For owls, who tend to sleep in on weekends, Cindy Zhou this could manifest itself as having to be up earlier on weekdays for work or school. Unlike the jetlag one might feel after taking a transoceanic flight, which is a temporary As class registration for the experience, SJL is permanent (Díaz-Morales upcoming semester rolls around, some of the & Escribano, 2015). Past studies have most common complaints are of early classes. correlated social jetlag with poor physical Are college students just lazy and love to and psychological functioning, including an sleep in? Or is there an underlying factor that increased risk of obesity, diabetes, depression, causes a large number of them to be so averse and reduced academic performance to earlier class start times? (Roenneberg et al., 2012; Parsons et al., 2015; This phenomenon can be explained Levandovski et al., 2016). The extensive list by the concept of chronotypes, which are the of adverse health outcomes related to SJL behavioral expressions of an individual's propels it forward as an emerging public circadian rhythm, often related to sleep and health concern. About a third of the activity patterns (Takahashi et al., 2018).
    [Show full text]
  • How the Intensity of Night Shift Work Affects Breast Cancer Risk
    International Journal of Environmental Research and Public Health Article How the Intensity of Night Shift Work Affects Breast Cancer Risk Marta Szkiela 1,2,* , Ewa Kusideł 3 , Teresa Makowiec-D ˛abrowska 4 and Dorota Kaleta 1,2 1 Department of Hygiene and Epidemiology, Faculty of Health Sciences, Medical University of Lodz, 90-752 Lodz, Poland; [email protected] 2 Department of Hygiene and Health Promotion, Faculty of Health Sciences, Medical University of Lodz, 90-752 Lodz, Poland 3 Department of Spatial Econometrics, Faculty of Economics and Sociology, University of Lodz, 90-255 Lodz, Poland; [email protected] 4 Nofer Institute of Occupational Medicine in Łód´z,Department of Environmental and Occupational Health Hazards, 91-348 Lodz, Poland; [email protected] * Correspondence: [email protected]; Tel.: +48-42-725-290 Abstract: Background—In 2019, the IARC concluded that “night shift work is probably carcinogenic to humans (Group 2A), based on limited evidence from human epidemiological studies and sufficient evidence of cancer and strong mechanistic evidence in experimental Animals.” The negative health consequences of night shift work may depend on how the night shifts are scheduled. The aim of this study was to investigate how the characteristics of night work affect the risk of developing breast cancer. Methods—A case–control study was conducted in 2015–2019 in the Lodz region. The case group included 494 women with breast cancer, while the control group included 515 healthy women. Results—Night work was found to be the third most important factor regarding breast cancer after a high BMI and a short or no breastfeeding period and before factors such as early Citation: Szkiela, M.; Kusideł, E.; menstruation, late menopause, no pregnancy, and smoking.
    [Show full text]
  • PDF Download Good-Night, Owl!
    GOOD-NIGHT, OWL! PDF, EPUB, EBOOK Pat Hutchins | 32 pages | 01 May 1990 | SIMON & SCHUSTER | 9780689713712 | English | New York, United States Good-Night, Owl! PDF Book Lovecraft [25] Marilyn Manson [26]. When you stay up really late, you can sometimes get ahead of yourself. Pages Home About. Can you see a noise? About the size of a pigeon, tawny owls are widespread across Europe, including about 50, breeding pairs in the U. I went back to bed. Night owls flout social norms in other ways, too: staying up late is also associated with doing more drugs and having more sex. If that doesn't work, there may be a network issue, and you can use our self test page to see what's preventing the page from loading. Baby carrots, bagged salads, rotisserie chickens, bananas, low-salt nuts, reduced-fat cheeses, whole grain crackers and bread can satisfy a lot of those late-night good mouthfeel snacks without adding unnecessary calories. Good Night Owl. Their feathers muffle noise and reduce sound when they're soaring through the air, so they often do so without anyone noticing. Got the 'Drunchies'? They've also recently expanded across parts of Canada into the Pacific Northwest, where they can outcompete the similar-looking but much rarer spotted owl. The rodent specialists can hunt by hearing alone, often diving to grab mice from underneath deep snow. Perhaps somewhat intuitively, one more piece of the puzzle is in, and it's not good news for night owls like me: people who stay up later at night spend more time sitting, and find it harder to fit exercise into their lifestyles.
    [Show full text]
  • Intelligence 47 (2014) 107–112
    Intelligence 47 (2014) 107–112 Contents lists available at ScienceDirect Intelligence Morningness–eveningness and intelligence among high-achieving US students: Night owls have higher GMAT scores than early morning types in a top-ranked MBA program Davide Piffer a,DavidePonzia, Paola Sapienza b, Luigi Zingales c, Dario Maestripieri a,⁎ a Institute for Mind and Biology, The University of Chicago, Chicago, IL 60637, USA b Kellogg School of Management, Northwestern University, Evanston, IL 60208, USA c Booth School of Business, The University of Chicago, Chicago, IL 60637, USA article info abstract Article history: Individuals with a propensity to wake up early in the morning (“early-morning” types) and those Received 15 January 2014 who like to stay up late at night (“night owls”) often exhibit distinctive psychological and Received in revised form 15 July 2014 physiological profiles. Previous research has shown that night owls score higher than early- Accepted 2 September 2014 morning people on different measures of cognitive ability and academic achievement. Baseline Available online xxxx cortisol is one of the physiological variables associated with variation in chronotype and cognitive function. In this study we investigated whether a relationship between chronotype and Keywords: performance is present also in the high range of intellectual ability and academic achievement, Chronotype namely, among graduate students in a top-ranked MBA program in the US. In addition, we Intelligence measured baseline cortisol levels in saliva samples collected in the early afternoon and analyzed MBA students them in relation to chronotype and GMAT scores. As predicted, GMAT scores were significantly GMAT scores Cortisol higher among night owls than among early-morning types, regardless of sex.
    [Show full text]
  • Early Birds Earn More Than Night Owls
    News from the August 2011 Going to bed late has its price: Early birds earn more than night owls How much does it cost you if your biolog- ical clock means you prefer going to bed late and getting up late? A Danish study has the answer. Early risers or “larks” – people who get up early, even on their days off – earn 7% more than their night-owl counter- parts, who sleep in when they are off +7% work. More precisely, for every £10.70 the early riser earns, the average late riser earns only £10.00. Salary This is the finding of a study which Salary compares sleep rhythms with income, carried out by the Rockwool Foundation Research Unit in 2008/09. In a Danish Time Use and Consumption Survey, 4000 A B people aged between 18 and 64 (74) years completed a questionnaire on what they had been doing in the last 24 hours, in- cluding when and for how long they had slept. The information on sleep was sub- new book Sleep – marriage, income and sequently correlated with information on health. their earnings. According to Jens Bonke, sleep is un- Initially, there is a good explanation for der-researched: “We know that sleep, or the difference in earnings: society caters lack of it, has bearing on virtually every- for early risers to a very high degree. The thing that is important in life. It influenc- vast majority of jobs start in the morning es relationships, children’s welfare, learn- and end in the late afternoon. Therefore, ing ability, labour market activity and the all things being equal, those who are at level of health.
    [Show full text]
  • Fatigue and Sleep Disorders
    FATIGUE AND SLEEP DISORDERS Daryl Wile, MD, MSc, FRCPC (Neurologist) Overview What is fatigue? Sleep disorders Fatigue ● What changes in PD ● What is it? ● Insomnia ● How common? ● Dream enactment ● General causes ● Restlessness ● PD specific causes ● Daytime sleepiness ● Approach ● Troubleshooting Dr. Wile reports no conflicts of interest relevant to this presentation Why does this matter? Fatigue Sleepiness Sleep benefit Worst problem: 33% Top 3 problem: 50% Sleep may have an impact on neurodegeneration What affects sleep (and vice versa)? Accumulation of adenosine Time awake and circadian rhythm Protein phosphorylation “I’m a night owl” Multiple genetic factors Hormones Caffeine and stimulants “Awake” hormones Cortisol Exercise Adrenaline / noradrenaline Natural light exposure “Asleep” hormones Melatonin Testosterone Artificial light exposure Growth hormone Erythropoietin Leptin Normal sleep stages REM sleep Later in night Dreaming Heart rate, breathing similar to awake Awake No muscle activity REM Stage 1 Light sleep Changes in temperature Decreased heart rate Less muscle activity Stage 2 Deep sleep Earlier in night Lowest temperature, heart rate, Stage 3 breathing rate, muscle activity Body and brain maintenance activities Sleep changes with aging Less overall sleep time Shorter time in each stage More time awake while in bed Neubauer DN. Am Fam Physician. 1999 May 1;59(9):2551-2558. Why is sleep affected in Parkinson Disease? Normal increase in melatonin at night Weaker in Parkinson Disease (especially if they report daytime sleepiness) Disruption of the circadian rhythm May start even before movement problems Changes in the brain’s sleep system Videvonic A et al. Circadian melatonin rhythm and excessive daytime sleepiness in Parkinson’s disease.
    [Show full text]
  • ACTIVITY - Are You a Night Owl Or an Early Bird?
    ACTIVITY - Are you a night owl or an early bird? Our bodies have an internal clock, called the circadian rhythm, that tells us when it is the best time for us to sleep, wake up, eat, do exercise, learn and a number of other things. Not everyone’s body clock is the same. Some people feel their best in the morning, while other people feel their best at night. Some people can go to sleep easily early in the evening, while other people have trouble going to sleep before midnight. Understanding your body clock will help you to understand what times of the day you are more productive and what times are the best for you to sleep. Instructions A. Read each question carefully B. Answer each question as honestly as possible. Do not go back and check your answers. Your first response is usually the most accurate C. Answer ALL questions. Questions 1. What time would you get up if you were entirely free to plan your day? Score Time (please circle) 5:00 – 6:29 am 5 6:30 – 7:44 am 4 7:45 – 9:44 am 3 9:45 – 10:59 am 2 11:00 – 11:59 am 1 Midday – 5:00 am 0 2. What time would you go to bed if you were entirely free to plan your evening? Score Time (please circle) 8:00 – 8:59 pm 5 9:00 – 10:14 pm 4 10:15 pm – 12:29 am 3 12:30 – 1:44 am 2 1:45 – 2:59 am 1 3:00 am – 8:00 pm 0 1 Prepared by Dr Sarah Biggs, The Ritchie Centre, Monash University 2015.
    [Show full text]
  • How to Travel the World Without Jet Lag
    Sleep Med Clin. Author manuscript; available in PMC 2010 Jun 1. Published in final edited form as: Sleep Med Clin. 2009 Jun 1; 4(2): 241–255. doi: 10.1016/j.jsmc.2009.02.006 How To Travel the World Without Jet lag Charmane I. Eastman, Ph.D.a,b and Helen J. Burgess, Ph.D.c,d a Professor, Behavioral Sciences Dept., Rush University Medical Center, Chicago b Director, Biological Rhythms Research Laboratory, Rush University Medical Center c Associate Professor, Behavioral Sciences Dept., Rush University Medical Center, Chicago d Associate Director, Biological Rhythms Research Laboratory, Rush University Medical Center a Corresponding author for proofs and reprints: Charmane I. Eastman, Ph.D., Biological Rhythms Research Laboratory, Rush University Medical Center, 1645 W. Jackson Blvd, Suite 425, Chicago IL 60612 USA, Ph. 312 563 4787, Fax. 312 563 4900, Email: [email protected] cCoauthor address: Helen J. Burgess, Ph.D., Biological Rhythms Research Laboratory, Rush University Medical Center, 1645 W. Jackson Blvd, Suite 425, Chicago IL 60612 USA, Ph. 312 563 4785, Fax. 312 563 4900, [email protected] Keywords: jet lag, phase response curves, melatonin, bright light, sleep, circadian rhythms Copyright notice and Disclaimer Publisher's Disclaimer See other articles in PMC that cite the published article. Several reviews on jet lag by us [1, 2] and others [3, 4] have recently been published. The focus of this article is on describing in detail how melatonin, bright light and sleep schedules can be used in conjunction with currently available flight times to reduce or eliminate jet lag. Our aim is to educate circadian rhythm researchers and sleep clinicians about the principles involved, so that they can make similar jet travel schedules customized for individuals traveling in any direction across multiple time zones.
    [Show full text]
  • Chronotypes and the Dark Triad Traits
    Personality and Individual Differences xxx (2013) xxx–xxx Contents lists available at SciVerse ScienceDirect Personality and Individual Differences journal homepage: www.elsevier.com/locate/paid Creatures of the night: Chronotypes and the Dark Triad traits a, b b Peter K. Jonason ⇑, Amy Jones , Minna Lyons a University of Western Sydney, Australia b Liverpool Hope University, United Kingdom article info abstract Article history: In this study (N = 263) we provide a basic test of a niche-specialization hypothesis of the Dark Triad (i.e., Received 14 March 2013 narcissism, psychopathy, and Machiavellianism). We propose that in order to best enact a ‘‘cheater strat- Received in revised form 26 April 2013 egy’’ those high on the Dark Triad traits should have optimal cognitive performance and, thus, have a Accepted 1 May 2013 night-time chronotype. Such a disposition will take advantage of the low light, the limited monitoring, Available online xxxx and the lessened cognitive processing of morning-type people. The Dark Triad composite was correlated with an eveningness disposition. This link worked through links with the ‘‘darker’’ aspects of the Dark Keywords: Triad (i.e., Machiavellianism, secondary psychopathy, and exploitive narcissism); correlations that were Dark Triad invariant across the sexes. While we replicated sex differences in the Dark Triad, we failed to replicate sex Narcissism Psychopathy differences in chronotype, suggesting eveningness may not be a sexually selected trait as some have Machiavellianism argued but is a trait under natural selective pressures to enable effective exploitations of conspecifics Morningness:eveningness by both sexes. Chronotype Ó 2013 Elsevier Ltd. All rights reserved. Evolutionary psychology 1.
    [Show full text]