While growing up, my mother would always compare me with kids that were smarter than me. This always gets me upset as a child and I would get angry with my mom for comparing me in such an unfair way. However, after going back home recently and seeing all my childhood friends that I got compared to when I was little, I realized one thing, almost all of them have larger heads than me. As a result of this, it made me curious to find out if having a larger head correlates with higher intelligence.
According to the guardian website, scientists found close correlation between the size of a person’s skull and the results of intelligence and memory tests. According to Dr. Christopher Martyn of Southampton University’s environmental epidemiology unit, “The larger a person’s head, the less likely their cognitive abilities are to decline in later years.” Martyn and his team conducted their studies based on a sample of 215 men and women aged from 75 to 80. Each person was given an initial IQ test and a memory test. After three years, the same group was asked to retake these exams and each person’s cognitive powers were then calculated. Then, individual’s head circumference were measured and recorded. As a result, it was clearly shown that there is a link between head size and the loss of memory and cognitive ability in later life.
Even though this study is very well conducted, it still can’t accurately prove that having a larger head means having higher intelligence. In other words, we cannot assume correlation means causation and there is always the possibility of chance happening. Confounding variables also plays a part in this situation. Did all the participants go to school? Are all the participants properly nourished at a young age? Are all the participants in good health? Another thing is this experiment is biased in age. They only experimented on older people. However, would we get the same result if the experiment were experimented on younger people?
As a result, we can’t assume that bigger heads means higher intelligence based on the data collected. We have to consider many more outside factors. Knowing this, it made me feel better that I have a chance to catch up to my friends even though my head is smaller than theirs.
http://www.theguardian.com/uk/2003/sep/28/research.health
http://gnosticwarrior.com/head-size-matters.html
http://science.howstuffworks.com/life/inside-the-mind/human-brain/brain-size2.htm
Jiang, I’m sorry to hear this made you upset as a child. Many of my friends in high school have had a similar experience with their parents so I’m familiar with this cultural comparison. But on another note, haha that’s funny, connecting their big heads to their intelligence. This idea made me think of Andrew’s commentary on big feet and literacy.
I thought that was an interesting study, but you’re right there are other factors to consider and chance, don’t forget there’s always the possibility of chance. Also, I don’t think the sample size was even large enough to draw the conclusion that head size was the cause, well yes, they found some correlation, but that isn’t enough. And why did they choose old people? I think even that itself is a little iffy. Maybe they would have achieved the same results with a younger group group, but I think, on paper, the data would seem a little more accountable if the sample size was of a younger age . Old people shrink and crumble a little over time anyhow lol I wonder if the scientists thought of that when they chose their participants.
If you makes you feel any better, I think your head is pretty darn big and you are a genius. Haha
I found your analysis to be very well-constructed, considering their level of education and sorts. While the studies do support the hypothesis, there wasn’t a large enough sample size to convince me of this. I would say I generally have a small head in comparison to my best friend and tend to do a lot better at school (even without studying). Katelyn brought up a good point, could age be a factor as well? I see this question a lot like the question of whether prayer heals. While scientists were able to manipulate data to prove the point, it is most likely a false positive.
http://www.smithsonianmag.com/science-nature/why-brain-size-doesnt-correlate-with-intelligence-180947627/?no-ist
This article describes a study done with animals to see if brain size correlates with intelligence. Just like the study you describe, scientists found that a bigger brain does mean greater intelligence. But apparently, this was part of the file drawer problem because these scientists didn’t publish that only two of ten animals actually supported their hypothesis. Hopefully this article is helpful!
There is a correlation between skull size and intelligence but correlation does not equal causation. Going along with what Katelyn said, they tested 75-80 year olds, does this mean we could generalize the new found information to people of all ages? Also confounding variables play a huge role in this because with testing people of this age they could be experiencing medical problems which we would not be able to control in the study. Although we can rule out reverse causation, we must consider the fact of chance. Just because someone has a large head does not necessarily mean they are intelligent and vice versa if someone had a smaller head that does not automatically mean they are less intelligent. This study would need to conduct more experiments to be able to determine if there is a correlation between the hypothesis or if it is just a false positive.
Here’s an interesting study on a different age range. Seems they found the same thing in babies. I kind of like this study a little more just because they followed these children for a longer time and did more than one checkup. It’s still faulty though. http://www.webmd.com/parenting/baby/news/20061013/bigger-head-smarter-baby
Interesting study! There is also always the possibility of chance. Correlation definitely does not equal causation and this study is a great example of that. In my opinion, 215 people isn’t enough participants to make a conclusion about the entire world, it’s just not a big enough sample size. I also have a problem with the age bracket they used. They conducted the study on 75-80 year olds, but could the results be different for 20-25 year olds? 30-35 year olds? The study also fails to eliminate confounding variables. It’s an interesting concept, but this study is very lacking. Great conclusion on your part though!