Does the size of your head mean anything?
Science says larger brains are correlated with higher intelligence, but size alone isnt the cause. Its common to hear people say that the size of your brain has nothing to do with your level of intelligence. So yes: On average, people with bigger heads tend to be more intelligent.
Is head size proportional to weight?
A relation between head circumference and brain weight of humans is generally believed to exist, but the literature contains only two studies which exhibit a quantitative aspect of the relation, showing that brain weight is proportional to the cube of the head circumference from birth through age 3.5 years.