Bigger Head = Higher Intelligence?

I remember that at an earlier age I would have been pretty upset if someone had told me that my head is big because I simply thought that a big head ran against the common aesthetic view about the body and head proportion of human.Then I have learned that the most common defense by people of bigger heads tends to be that "it is because I'm smarter". The logic is that a bigger head implies a bigger brain and thus a higher intelligence. Is this scientifically true?

I did a little search over the internet and has found this short piece of news from The Independent, which came out on Oct 21st, 2007. It states that "new scientific research proves that people with big heads have higher than average intelligence." "Edinburgh University researchers, using MRI scans and IQ tests on 48 volunteers, discovered that the larger the head, and therefore the brain, the greater the IQ. A person with a brain of 1,600cc has an IQ of around 125." The news also cites another expert's argument as confirmation of the scientific result. "Dr Alasdair MacLullich of the university's Queen's Medical Research Institute said: 'As a general rule, the larger the dimensions of front to back and side to side, the greater the IQ, although, of course, there will be exceptions.' "

While it seems to me somewhat convincing of the piece of news, I have come up with the question whether head size fully suggests brain size. Then I have found another piece of information from the website "Science Netlinks" which draws on scientists' arguments regarding the issue. It reports that "Grant Hurlburt, a visiting professor of biology at California State University in Bakersfield says measuring the size of the head does give some indication of how big the brain is". He says: "Even though head size also depends on factors such as the muscularity of the head and thickness of the bone, it's very likely that a bigger head means a bigger brain." However, the professor also suggests that "people with bigger brains aren't necessarily smarter than those with smaller ones. Studies have shown a weak correlation between brain size and I.Q. But scientists aren't sure what causes it".

Therefore I have decided not to totally believe in the first piece of news but accept the idea that head size might have some positive correlation with brain size. In fact, some people I know that have relatively big heads are indeed smart and have achieved high academically while some others have not. So I really cannot tell. Interestingly, I also have found out that the range of human man brain size is actually quite large: a study of 46 adults aged 22-49 years and of mainly European descent, found an average brain volume of 1273.6cc for men, ranging from 1052.9 to 1498.5cc, and 1131.1cc for women, ranging from 974.9 to 1398.1cc.( from Wikipedia, "Brain size"). Thus I really wonder whether people of the biggest brain size like 1498cc are much more likely to be smarter.

The sources of the news:

1. http://www.independent.co.uk/news/science/people-with-big-heads-have-higher-intelligence-395116.html
2. http://sciencenetlinks.com/science-news/science-updates/big-heads/
3. http://en.wikipedia.org/wiki/Brain_size#cite_note-Allen2002-13