Sleeping longer can help improve your grades! Or so the Straits Times seems to claim… Is it really true?
“Sleep plays a fundamental role in the way we learn.”
“optimal quantity of sleep leads to more effective learning in terms of knowledge acquisition and memory consolidation.”
“Poor quality of sleep – caused by lots of waking up during the night – has also been reported to be a strong predictor of lower academic performance”
“Our study shows that a longer period of sleep and earlier bedtimes – measures of sleep quantity – most strongly correlated with better results obtained by the students on a number of tests at school.”
Wow, it sounds really interesting! The correlation between students’ GPA and Total sleep time is r=0.43 (That means that there is a significant linear relationship/ pattern between GPA and Total sleep time). The correlation between students’ GPA and Bedtime (on weekdays) is r=-0.39 (similarly, a significant linear pattern, but in the opposite direction; Earlier sleep is linked with better grades). But wait, no where in the journal is CAUSATION mentioned! All the above correlations show is a pattern! Could it be that maybe, the students who do better in their GPA are relatively smarter and tend to have more time to rest and sleep?
Well, even ignoring that, could it be that the issue is not so much about “Sleep and GPA”, but more about “usage of social media/ TV and GPA”? Some science papers do believe that media usage just before sleep, is able to change the body’s natural circadian rhythm (biological clock). Some sources claim that 0.5hr of TV usage, can significantly alter the circadian clock, thus affecting sleep quality and quantity. On top of that, the pressence of light may even reduce melatonin levels, which are responsible for helping the body to sleep. If students are very prone ot use social media/TV, they also may spend less time on their studies, hence the big issue may be about usage of social media and TV?
The sample size is 48 students from a particular college in London. Is it possible that these students are all chosen conveniently, and have certain traits? EG: Most of the students seem to do well in their grades (average 72 marks), and most of the students seem to slp more than 7 hours (average 7.08hours), so that non-random choice of subjects already may begin to influence the way we look at the relationship between Sleep and GPA.
Overall, sleep does seem like a possible variable to influence our grades, but to jump the gun like the newspaper would be a huge logical leap of faith. Perhaps all we can really conclude from these results is that there is a pattern!