What makes some people smarter ?

There are many reasons. People possess different levels of potential.
Some of it is genetic. Some of it is environmental. And a lot of it is motivation.

I'm not smart enough to know why.

My brain is smarter because of the smooth, glossy folds, the charming dove gray tones, the . . .

Oh . . . you mean smarter as in more intelligent . . . not more stylish . . . nevermind . . .

I'm really smart, it's my brain that's faulty.

Rice Krispies and a good rare steak!

Well, that's more or less what put us ahead of the chimps...

I dunno . . . if reincarnation were a fact, i'd wanna come back as a bonobo . . .

Randy bugger... er...

Phoenix, Motivation may make us inclined to learn more, but can we be motivated to increase our intelligence?

Knowledge is a burden, to hell with it.

Setanta, you don't want a smooth brain. The more folds, the more surface area and hence intelligence is enhanced (we learned that in H. S. Bio. See: http://faculty.washington.edu/chudler/brainsize.html for a quick explanation). It also helps if the cerebrum is more developed, as this controls higher functions, whereas the cerebellum handles motor control.

Intelligence is more than physical smarts, which are going to come from heredity, gestation (better prenatal care generally means smarter children, or at least poor prenatal care can result in brain damage, like fetal alcohol syndrome) and environment (e. g. ingestion of lead leads to brain damage).

Intelligence is also education; that is, the smartest person in the world is not so "smart" if they aren't given challenges. This goes along with Phoenix's idea of motivation. It's one thing to be extremely good at arithmetic, versus being extremely bad at advanced calculus. Who's smarter? I posit that the one who's bad at calc is smarter, because it's more of an achievement to work at calc - even if you barely understand it - than it is to rotely spit back the answers to addition problems.

Can you develop intelligence? I'd say yes, to a certain extent. You can't physically improve your brain, or at least we can't at this stage of medical history. However, you can challenge yourself. Do things that are intellectually difficult. This means things like puzzles, riddles and logic problems. You will eventually work out how to do them, if you keep at them long enough. Read more difficult books. It need not be theoretical physics, but reading Proust is harder than reading Stephen King. This is another way to challenge yourself. Another way is to take classes or at least do the readings for advanced classes. Try to learn a foreign language. Tackle programming. Develop artistic, musical or design creativity. Read Philosophy or scientific treatises. I'm not saying that it can all be absorbed, and (much like with physical challenges) you should start small and work your way up. But I think most people can, if they work hard enough and they try hard enough, get at least a fundamental understanding of what may seem at first blush to be rather difficult material.

Oh and another thing - with intelligence, it's often use it or lose it. Education, sadly, ends at age 18 or 21 or 25 for many people. Why not continue it? It doesn't have to be something wholly unpleasant in order to be intellectually stimulating. If foreign languages don't interest you, learn about art. If that doesn't interest you, read advanced material about science. There are thousands of areas of study out there. The pity isn't in trying and failing; the pity is in failing to pursue any of them.

I'm stylin', Boss, you think your way an' i'll think (to whatever limited extent), my way . . .

Stephen King THRILLS me...I like being DUMB!

I watched a Mr Bean cartoon on PBS last night. Since it was on the smart channel I must be pretty above average, hey?

Jes, I agree and disagree with your comments. I think that it's important and invaluable to remain sharp and challenge ourselves. I think that such activities as you mention do keep our brains active. However, I don't think that all the motivation, study, and intellectual challenges in the world can make an unintelligent person smart. I think they can help an unintelligent person reach full or close to full potential.

I've read studies that suggest it's possible to become smarter. Actually increase our intelligence. But I believe that we are each limited within the range of our physical abilities.

So, although intelligence can be a combination of nature and nurture, I'm inclined to think that nature limits what we're able to nurture.

No question that there are limitations. Not everyone is going to "get" Stephen Hawking. Try as I might, my creativity isn't great - I'm still a lousy painter, even though I've been doing it (on and off) for a few years. I'm sure I'll never be an expert on the Athabascans. So be it.

What gets me is when people don't exercise their intellects. I'm not saying that you have to take medicine every single day or that you have to wade your way through Kierkegaard at every possible moment. Ugh, I don't live like that and I don't expect anyone else to do so unless it gives them pleasure. But I think a little stretching is helpful if not necessary. Right now I'm in class for something I didn't think I could do. It does not come easily. I continue to fear that I won't get it. But I'm finding that trying is a good thing.

Roberta Agree, to some extent. I forget what the figures are, but I have read in a number of places that humans only use a small percentage of their potential brain power. Yes, there are genetic limitations, but ALL people can achieve more through motivation and the exercise of their minds.

There is another issue here. People tend to like and go towards what comes easy to them, and avoid those things that are more difficult. Therefore, by never practicing those mental skills in the more difficult areas, after awhile, whatever skills that one has originally in the more difficult areas, atrophies.

We all eat a lot of very hot and spicy chili.

To answer this question you need to define what "smart" means and how to measure it. Based on which definition you choose, you can get different answers to your question.

(This is an interesting and relevant question to me becuase I am working on developing educational materials for algebra students who are not overachievers.)

One way educational theorists measure 'smartness' is the ability to do certain mental tasks. Piaget (a rather famous thinker about these things) identified what he called "formal operations". These involve certain tasks that require well-defined levels abstract thinking skills.

My impression from the research is that after a certain level (i.e. adolescence) people can not learn these skills. Once you are an adult, you either have these skills, or you don't -- and it is unlikely you will ever have them.

One of my mentors claims that, for example, there are certain topics in science that are not worth covering in any depth. A small minority of students will get the idea right away. The rest of the students will never get them.

I am uncomfortable with the ideas that people can not get "smarter". As an educator I like to think that anyone can improve with practice. But the reasearch seems to say that this doesn't happen.

As far as how much this has to do with genes and how much has to do with your childhood is an open question.

But it appears that once you are an adult, you don't change.