The Effect of Age on Hours of Sleep

By: Varsha Kanneganti, Janice Kao


Does age affect the amount of sleep you get on a work night?


Adults will have a greater amount of sleep than high schoolers' on an average work night.

Type of Investigation

This questionnaire was a comparative investigation.

Parts of the experiment

  1. Independent Variable: Age

  2. Dependent Variable: Hours of Sleep gotten

  3. Control: None

  4. Experimental Groups: adults (ages 19-up, both genders), high schoolers at CHS (ages 14-18, both genders)

  5. 2 Factors Held Constant: kind of night the sleep is gotten on (work night), the questionnaire questions

Data Tables

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T-Test Value: 0.02691108784

Bar Graphs

Bar Graph including Error Bars for ±2 SEM
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Bar Graph including Error Bars for Range
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This experiment illustrated that adults got more sleep than high schoolers on an average weeknight or work night. The average hours of sleep adults got each work night, approximately 7.7 hours, was larger than the average hours of the high schoolers, approximately 6.5 hours. When looking at the graph with the error bars depicting ± 2 standard errors of the mean, the error bars do overlap, but only by a small amount. Because the error bars do not overlap many of the same numbers, the independent variable, which was age, did affect the results. Additionally, when a t-test was conducted, the p-value gotten was 0.03. Because the p-value was below 0.05, there is at least a 95% confidence that the null hypothesis (age had no effect) is incorrect. Scientifically, as adults age, the slow-wave sleep stage that has the most restorative effects is replaced by a less restorative stage (Shaw). Because adults have a shortened restorative stage in sleep, their sleep tends to be less satisfying and restorative (Cicetti). Also, as people age, more health problems tend to interrupt the rhythm of their sleep; thus, adults sleep more to make up for the time lost from disruptions in sleep and to completely re-energize themselves (Shaw).

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The hypothesis was supported and the purpose was also achieved. In this experiment, adults did have a greater amount of sleep on an average work night.

Sources of Errors/Inaccuracies

When doing this questionnaire, there were many steps; there was bound to be human error. One of the errors that stood out from the test subjects was the fact that they had to estimate the number of hours that they get to sleep on a work night. They may incorrectly recalled how many hours of sleep they got the other night. In addition, the data could have been more specific if we had asked them to time how many hours of sleep they got on a work night. Another error in collecting answers would have been a term called social desirability bias. Typically in surveys, social desirability bias may skew the results. Social desirability bias refers to the instance in self reports where people may report inaccurately to present themselves in the best light (Fisher). For example, high schoolers tend to think of it as a competition to say they’ve slept the least; thus, they may report themselves as sleeping only five hours each school night. Adults are also susceptible to the social desirability bias as well.


Cicetti, By Fred. "Do Older People Need More Sleep?" LiveScience. TechMedia Network, 10 May 2009. Web. 06 Sept. 2015. <>.

Fisher, R. J. (1993). “Social desirability bias and the validity of indirect questioning“. Journal of Consumer Research, 20, 303-315.

Rettner, Rachael. "Man Comfortably Sleeping in His Bed." Fox News. FOX News Network, 03 Aug. 2012. Web. 04 Sept. 2015. <>.

Shaw, Gina. "Adult Sleep Needs at Every Age: From Young Adults to the Elderly." WebMD. WebMD, n.d. Web. 03 Sept. 2015. <>.

Sleep deprivation. Digital image. Cfah. Cfah, n.d. Web. <>.