November 1st, 2010
12:01 AM ET

Why party animals are always sleepy

Do your personality and social life say something about the way you sleep? According to a new study in the journal Sleep,  patterns of sleep can be based on the kind of social activities we partake in, and the type of people we are.

The study results showed that people who were outgoing, or extroverts, who were exposed to 12 hours of social interaction, were more vulnerable to being sleepy than those extroverts who participated in 12 hours of isolated activity. Response tests showed that extroverts who had great social lives were slower in the early hours of the day, as well as noon time, compared with extroverts who were by themselves. For those who were less outgoing, or the introverts, their response tests were unaffected and remained stable no matter what their activities.

"Extroverts exposed to socially enriched environments showed greater vulnerability to subsequent sleep deprivation than did extroverts exposed to an identical but socially impoverished environment," said principal investigator and lead author Dr. Tracy L. Rupp, a research psychologist in the Behavioral Biology Branch of the Center for Military Psychiatry and Neuroscience at Walter Reed Army Institute of Research. "The ability of introverts to resist sleep loss was relatively unaffected by the social environment. Overall, the present results might also be interpreted more generally to suggest that waking experiences, along with their interaction with individual characteristics, influence vulnerability to subsequent sleep loss."

The study looked at 48 healthy adults between the ages 18 and 39. Participants were prescreened using a standard personality test and were classified as either extroverted or introverted. After eight hours of normal sleep, all were asked to remain awake for a total of 36 hours, 12 of which involved some form of social exposure. Half the group was asked to take part in "socially enriched" activities, such as playing cards, board games, puzzles, watching movies or group discussions. The other group members were given an activity to do, by themselves in an isolated room. After the activities they were asked to stay awake for  22 more hours.
Throughout these activities, participants' wakefulness and alertness were measured. Researchers found there were no significant differences when extroverts and introverts slept for a normal eight hours. But when their alertness was tested during their hours of sleep deprivation, the introverts in the socially involved group, were more alert than the extroverts in that same group. And those extroverts who were socially active had more fatigue than the extroverts who were in the isolated group.

Study authors believe the combination of an outgoing personality along with an active social life could lead to rapid fatigue in certain areas of the brain that regulate attention and alertness. So high levels of activity with some people could be associated with the need for more sleep. However, investigators believe some people have a resistance to sleep loss that could be rooted in their genetic makeup. For instance, introverts may have a higher level of different chemicals and hormones in the brain that gives them an ability to stay awake and functional, even with a lack of sleep.

Rupp believes the data could help industries who require employees to work during odd hours of the day, better understand who's right for particular jobs.

"These data have practical relevance for occupational shift work and military operational assignments, said Rupp. "And can give them a better understanding individual-differences that can influence a person's vulnerability or resiliency to sleep loss."

soundoff (167 Responses)
  1. grammar grandma

    It's spelled extravert.

    November 1, 2010 at 13:08 | Report abuse | Reply
  2. Aaron

    Really, people who do more tire easier than those who don't?


    November 1, 2010 at 13:22 | Report abuse | Reply
  3. Southernguy

    I could of told these people this with out doing a lengthy study on it! All they have to do is stand outside of a club at 3am in the morning and ask what every ones plans are going to be for the following day.....the answer is easy.....SLEEP!

    November 1, 2010 at 13:24 | Report abuse | Reply
  4. brad1001

    "Those who can, do .. those who can't, teach. These PHD pinheaded academics are squandering public monies that could certainly be better spent.

    November 1, 2010 at 13:24 | Report abuse | Reply
  5. Christina

    Gee i never knew that I would be sleepy if I was up partying all night. Thanks for the writing the dumbest article I have ever seen on CNN.

    November 1, 2010 at 13:35 | Report abuse | Reply
  6. ghost

    anybody reading this study is an intronerd

    November 1, 2010 at 13:36 | Report abuse | Reply
    • Really

      I know you are but what am I?

      November 1, 2010 at 13:38 | Report abuse |
  7. Jay

    I was going to make fun of this article, but after some thought, there is some truth to these findings. I'm an introvert and my girlfriend is an extrovert, and though we have very similar social lives, she is generally more tired than I am at any given time.

    But really, how are employers supposed to know what personality type a potential employee is? I know that as an introvert, I can easily feign extroversion for a job interview.

    November 1, 2010 at 13:37 | Report abuse | Reply
    • KDW

      There are psychological tests that look at introversion and extroversion. If you have ever taken an intro to psych class you more than likely would have taken one. You get a profile that tells you what your personality is like on something like 7 different features with extroversion/introversion being one of them. Employers could easily add this as something that you take prior to accepting a position. Sort of like being drug tested before taking a job.

      November 1, 2010 at 13:45 | Report abuse |
    • KDW

      It has been pointed out to me that the pre-employment suggestion sounds a bit discriminatory. I will cede that point. However this still could be useful information when choosing soldiers for missions or which pilot to fly a long flight. Neither of these are discriminatory suggestions. Soldiers already undergo psychological testing and this information would be readily available for decision purposes. I believe pilots undergo similar evaluations as well.

      November 1, 2010 at 15:56 | Report abuse |
  8. Really

    This is the dumbest thing I have ever read.

    November 1, 2010 at 13:37 | Report abuse | Reply
    • Yeah

      And your the dumbest prson I ever met

      July 30, 2012 at 13:32 | Report abuse |
  9. vipul

    People, this is NOT saying that if you stay up longer by partying, you will be sleepy. Realize that ALL GROUPS GOT THE SAME AMOUT OF SLEEP. While they were awake (again, the same length of time), they got more or less interaction with people. Extroverted people who got more interaction were sleepier, having slept the same amount as everyone else previously. Amount of interaction didn't affect the introverts. This is a non-obvious and interesting finding. "Water is wet" comments are misplaced.

    November 1, 2010 at 13:38 | Report abuse | Reply
  10. KDW

    It never ceases to amaze me the lack of reading comprehension of people or the ability to decide from a news snip-it that a line of research is not worthy of being done. I think it is interesting that introverts are less impacted by social interactions than extroverts. It could be very beneficial when looking at the right person for jobs that require long hours of awake time (pilots) or shift workers (nurses). Personally I would want my night nurse at the hospital to be an introvert after reading this. They would be less likely to make medical errors and more likely to notice a problem as it arises. I also think it is surprising that their sleep is less effected than the extroverts. This would be a great area to look into further. Do they engage in conversation less and listen more? Are they less animated in their movements/gesture during games/conversation? Are there inherent differences in their brains that make them able to stay awake longer without getting sleepy? The article left out if there were any differences b/tw introverts under the two scenarios. This makes me think that there was probably no statistical difference. It would be really fascinating to know why that is.

    November 1, 2010 at 13:40 | Report abuse | Reply
    • Ella Jay

      get off your high horse LOL: it's 'snippet' :-p perhaps people have problems with reading comprehension when others use words with which they are not familiar?

      November 1, 2010 at 14:09 | Report abuse |
    • Ella Jay

      also, awesome job-screening suggestions there. just ask them on their application whether they are introverted or extroverted. i mean, we already can discriminate on people based upon what we see – gender, obesity, race – so let's make sure we don't miss any other areas by which we can rule out otherwise-potentially-productive individuals.

      November 1, 2010 at 14:10 | Report abuse |
    • KDW

      sorry that my proof reading offended you. But the point still stands. Many people commenting seem not to understand the basic premise of the research. Given the same amount of sleep an introvert engaging in social activities is not as tired as an extrovert engaging in the same activities. This is worthy of research and should not be dismissed in such a derisive manner as many posters are doing. As far as the suggestion for looking at employment. You may have a point, but there are many instances in which someone could use this to make decisions. You could decided what soldiers would be best suited for certain missions or which pilot would be best to use for a long flight.

      November 1, 2010 at 14:45 | Report abuse |
    • Bill Clinton

      Just the title of the article is lackluster and without thought.

      November 1, 2010 at 15:06 | Report abuse |
    • KDW

      I agree the title is very poor and has nothing to do with the results that were found. I guess getting people's attention is more important than coming up with accurate depictions.

      November 1, 2010 at 15:19 | Report abuse |
  11. Merry

    it's probably more like people who are introverts are less likely to become bored after long hours of wakefulness unlike extroverts who drop at the slightest decline in stimulation.

    November 1, 2010 at 13:40 | Report abuse | Reply
    • KDW

      I actually think this is a good theory. Not one I had thought of yet. Kudos to you.

      November 1, 2010 at 13:49 | Report abuse |
  12. Melissa

    Just a thought but... they're always tired because they're always awake too long and up too late. Anyone with a brain knows that.

    November 1, 2010 at 13:42 | Report abuse | Reply
    • KDW

      And now everyone knows you have trouble with comprehension. Everyone in the study stayed awake for the same amount of time, wether they were introverted or extroverted. The introverts who engaged in social activities were not as tired as the extroverts that engaged in social activities. This is surprising.

      November 1, 2010 at 13:51 | Report abuse |
  13. Jay

    It took a research study to determine that if you party all night, you're sleepy? Good gracious...brilliant.

    November 1, 2010 at 13:55 | Report abuse | Reply
  14. giggity75

    Anyone know how to get a job collecting data on these worthless articles?

    November 1, 2010 at 14:02 | Report abuse | Reply
  15. Ella Jay

    the Izzy/Alex thing was more 'news' than this was. i mean, we didn't know before that the producer nixed a plotline (which apparently would have made many people happy). but we DID know before that the less you sleep, the more tired you are. at least i HOPE we knew that .... :-/

    November 1, 2010 at 14:02 | Report abuse | Reply
    • KDW

      What we did not know is, that given the same amount of sleep an introvert will not be as tired as an extrovert. I guess after getting to my typo you failed to read the synopsis I gave of the article. You also did an excellent job proving my point, that people were being overly dismissive of the result due to a lack of understanding of what was written. Thank you.

      November 1, 2010 at 14:55 | Report abuse |
  16. Not so Obvious

    So... if you are an introvert you can party longer and be more alert while doing it... UNTIL... your introvert status is revoked for socializing too much... oh no my head is starting to hurt again.

    November 1, 2010 at 14:11 | Report abuse | Reply
    • KDW

      Introversion/extroversion is considered to be a very stable personality trait. Increasing your level of social interaction should not change how you would score on psychological evaluations of this trait.

      November 1, 2010 at 14:49 | Report abuse |
  17. outawork

    CNN did you run out of real news?

    November 1, 2010 at 14:16 | Report abuse | Reply
  18. chad crowder

    This study was a wast of time an money if any. Of course when someone is exerting energy then they will be less alert then thoes in the room alone. Wow thats just common sence you had to do a study for that geese

    November 1, 2010 at 14:17 | Report abuse | Reply
  19. Joe

    If you give me a million dollars, I will conduct a related survey that concludes that runners who spend 12 hours sitting are less tired than runners who spend 12 hours running. I'm all for research, but geeze, come up with something more useful!!!

    November 1, 2010 at 14:19 | Report abuse | Reply
  20. mike

    another garbage story from CNN. I think they have been outsourcing this content to 3rd world countries. I am done, no more cnn.

    November 1, 2010 at 14:24 | Report abuse | Reply
  21. KPATL

    You're kidding me right? Everyone who read this is more stupid for doing so,.. unfortunately, that mean me too! JEEEZ!
    Dear Editor,... please fire yourself for allowing this to be printed.

    November 1, 2010 at 14:34 | Report abuse | Reply
  22. Foz-man

    This story has been brought to you by the word "Duh"!

    November 1, 2010 at 14:36 | Report abuse | Reply
  23. ss

    I just went to sleep reading this article...not sure if this makes me an intro or extrovert. What a f*&ing stupid research

    November 1, 2010 at 14:45 | Report abuse | Reply
  24. NoSuchThingAsAnOpinion

    Do you wonder what the views of the smartest people in the world are?

    November 1, 2010 at 14:48 | Report abuse | Reply
  25. Marc

    Gee, how can I get paid to be a "Researcher of the Obvious"?

    November 1, 2010 at 14:57 | Report abuse | Reply
  26. Bong Water

    I stopped feeding my cat to see if it would get hungry.
    It did.
    Now where is my grant money ?

    November 1, 2010 at 15:03 | Report abuse | Reply
    • angie

      that's hilarious, I know right???

      November 1, 2010 at 15:31 | Report abuse |
  27. Corvus1

    Interesting article.

    CNN should do a study on their commenters' reading comprehension skills next.

    November 1, 2010 at 15:08 | Report abuse | Reply
    • KDW

      I have a feeling that would turn out to be a very poor result.

      November 1, 2010 at 15:21 | Report abuse |
  28. angie

    This is so stupid. The whole time I was reading it I thought, Isn't this so obvious? You do more- you have to sleep more!! What a dumb hypothesis!!!! Who came up with this anyway!!!! You might as well research the history of unicorns!

    November 1, 2010 at 15:30 | Report abuse | Reply
    • KDW

      What was found was that if you are extroverted and engage in social activities you are more tired than someone who is introverted who engages in the same activities. The fact that there was a difference between the two personality types is surprising. I'm quite sure the researchers were expecting to see a difference between the quiet activity and social activity groups, which they did, but were not expecting a difference between the two different personality groups.

      November 1, 2010 at 15:44 | Report abuse |
  29. Anatasia Beaverhausen

    I am personally working on a research project that involves watering grass and whether or not this makes the grass greener and grow faster. I am still looking over the numbers before reaching any conclusions.

    November 1, 2010 at 15:43 | Report abuse | Reply
  30. woodie

    I'm tired from listening to the extroverts burn themselves out. Extroverts should have an 'off' button.

    November 1, 2010 at 16:00 | Report abuse | Reply
  31. Stoprunning

    Wait, so if I stay out all night doing stuff, I will be tired the next day??


    What a CONCEPT

    November 1, 2010 at 16:00 | Report abuse | Reply
  32. KDW

    I don't know why this bothers me, but most people commenting seem to not have read the article. Everyone stayed up the same amount of time. Half the extroverts and introverts were in a low social interaction group and the other half were in a high social interaction group. Those in the low social interaction did not show as much fatigue as those in the high social interaction. This is not surprising. What was surprising was that in the high social interaction group extroverts showed more signs of fatigue than introverts. The question it raises is why would a personality trait impact how well you deal with fatigue given the same amount of activity.

    November 1, 2010 at 16:17 | Report abuse | Reply
    • eeyore

      You must be new here. Most of the articles of this nature are followed by posts decrying the "waste of money" studies like this presumably entail, the "obviousness" of the conclusions reached and the lack of newsworthiness of such articles. Predictable as night following day.

      November 1, 2010 at 19:54 | Report abuse |
  33. Olivia Alex

    Hello, slow news day.

    November 1, 2010 at 16:23 | Report abuse | Reply
  34. Heather Jeane

    Ooooooh I get it now. This article IS the study! They are trying to find out how many and what type of people will make misinformed public comments on a story based solely on the title of the article without reading the actual content.

    November 1, 2010 at 16:59 | Report abuse | Reply
  35. random30

    In other news... Research has shown that when it rains, things get wet.

    November 1, 2010 at 18:01 | Report abuse | Reply
    • eeyore

      And when those who have nothing else to do comment here, it's mostly to post some brain fart.

      November 1, 2010 at 19:54 | Report abuse |
  36. kryten

    I was at a Brain Imaging conference a few years ago and there was a great paper on sleep deprivation and aggression. I am glad to see good work being done in this area by Dr. Rupp. One of the areas of concern in that paper was police being sleep deprived and consequences that result. I am sure, given Dr. Rupp's work at Walter Reed, that this is a concern of the Army. BTW, I am always amused when I hear people with little or no scientific education (or any education, for that matter) comment on medical research. I suspect these people get their scientific news from Rush Limbaugh. Many of these posters sure sound like Sarah Palin!

    November 1, 2010 at 23:54 | Report abuse | Reply
  37. AW

    The title of the article is misleading (like the one titled "oral-sex leads to intercourse)... I wish CNN would stop doing this, I know it stimulates interest/advertising, but it's very irresponsible and just causes people to post completely misinformed comments.
    As for the article itself, the comparison between personality types is interesting, applicable, and NOT obvious. All of the people posting on here that it's worthless research aren't reading closely or aren't thinking critically...it's not an article about sleepiness vs. activity level, it's comparing how different personality types process the same exact situations differently. Furthermore, even if it's was a bad, totally pointless article that was a waste of time, I wasted far more time reading all of the comments like "this just in, the sun rises." The hypocrisy is comical.... I mean if you're upset about something being pointless or redundant, then why post a completely unoriginal comment that just echoes everyone else? I mean how many times did I read, "this just in, water is wet." Sometimes this comment was posted back to back.... do you people really not see the irony in that?

    November 2, 2010 at 08:14 | Report abuse | Reply
  38. checkdent

    You get sleepy if you don't sleep enough. I have allnighters but I get my 6 hour sleep after that and I'm not at all sleepy.

    November 2, 2010 at 10:13 | Report abuse | Reply
  39. DD

    If you read the actual paper, you will find that the results are quite compelling and help explain why some people just can't seem to function effectively without sleep and others can. It makes total sense to conduct this kind of study because it helps us to understand who can function more effectively without sleep in some situations and how that interacts with various cognitive factors. Personally, I would prefer to select a special forces operator, or airline pilot, surgeon, or whatever, who could sustain and outperform during times of stress or sleep deprivation. People's lives may depend on it. You can make fun of it, but if my life was on the line, I'd be glad that somebody was taking the time to think about who was best suited for a dangerous occupation.

    November 2, 2010 at 13:42 | Report abuse | Reply
  40. Ray Bordier

    Just started crapping in my pants. So much easier to clean-up. My hands were turning brown.

    February 7, 2019 at 13:35 | Report abuse | Reply
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