|MadSci Network: Neuroscience|
Hi Andy! Glad to have a question from Minnesota! I did my graduate work at "the U" (U of Minnesota) and thus have many good memories about the area (and one of my best friends lives in Edina too). Now, on to the real reason you wrote. You ask a timely question. Increasing a person's intelligence is perhaps one of the most sought after goals in all of science. Almost everyone has probably wanted to be a little bit smarter at some point in time - either to do better in school, or to answer those standardized test questions better, or just to be able to understand things more completely. But can we actually do anything about it? Well, no and yes. To begin with, you need to think about what we mean by intelligence. Nowadays, intelligence is usually taken to be some form of test performance - sometimes on an IQ test or some other standardized testing procedure. There are many people who believe this is a flawed way to get at intelligence. For instance, can one type of test measure intelligence and boil it down to some number? Many people believe there are types of intelligence that are difficult to measure in a regular test format (like "street smarts" or social intelligence). Another potential problem is that of cultural differences. Can a test constructed by researchers in the USA accurately assess the intelligence of people who have been raised in different countries and cultures? This last issue has really created a firestorm of controversy as there appear to be racial differences (Asian-Americans, European-Americans, African-Americans) on many types of standardized tests (like IQ and the SAT). However, whether these are meaningful differences is an entirely different question. The second thing you need to know is that how "intelligent" you are (according to these types of tests) does change over time. This is because each score is often a ratio of how well a person does divided by how well they should do according to their age or maturity. So it is possible for someone to get "less smart" as they get older if they performed really well when they were younger. In reality they would not be less smart - they were just advanced for their age when they were younger. Likewise, if someone is a late bloomer, they may seem less smart at one point in time and then appear to get smarter. This might also happen if something changed in your environment (example: going from a not-so-good school to a better school) that might impact how well you tested. But can we make people smarter? There are two parts to this question. The first is getting at whether there are "smart" genes in our DNA. The Human Genome Project is nearing conclusion - and the main goal is to sequence, or read, all of the DNA that we have in our cells to determine which genes control what behaviors. Of course, the one very important behavior many people are interested in is intelligence. Having "smart" genes may not make sense - but if you consider that intelligence is a trait just like eye color or height, then it does makes sense. If there are genes for eye color (and there are!) then there probably are genes for intelligence (or something like intelligence). For many years, researchers have known about genetic differences in intelligence by studying twins. You probably remember from your biology classes that there are 2 types of twins: identical (or monozygotic; developing from one fertilized egg) and fraternal (or dizygotic; where 2 eggs get fertilized and develop at the same time). Identical twins share all the same genes, whereas fraternal twins are basically just like brothers/sisters who share the same birthday. Now the trick is to compare identical and fraternal twins. The reason to do this is that we know how much of their genetic material they have in common (identical twins share all, or 100%, whereas fraternal twins only share about 50% of the same genes). What researchers have found is that identical twins usually perform nearly the same on many types of IQ tests. Fraternal twins on the other hand, do not score the same as each other. Why do the fraternal twins score differently than each other? Since they are a set of twins, we know that they have been through many of the same experiences. So the environment is the same (or pretty close) for each twin. So the only real difference between the fraternal twins is their genes. Thus we conclude there must be some genetic influence at work. The second part is whether we can make people smarter - by doing something to them - perhaps making them take a class, or maybe by giving them a smart pill. You no doubt have experienced the "practice-makes-perfect" analogy that parents and teachers always tell us. It is true - practicing something (reading, writing, throwing a frisbee, playing the piano) does make you better at it - but does it make you smarter? Probably not. You most likely are just improving your performance. Some people take classes to help them do better on some types of college-entrance tests (like the SAT). Many college students take classes to help them do better on the tests that are required to get into medical (MCAT) or law school (LSAT). But does taking these special classes make them smarter or more intelligent? No. It is more likely that they are improving their abilities to take the tests - such as improving their time management skills, learning better ways to approach a type of difficult question, or easier ways to recognize potential wrong answers. Recently there was a lot of attention given to a study that examined the effect of playing music by Mozart to children. The original study reported that listening to Mozart increased the intelligence of the children. So everyone went out and started buying Mozart CDs to play for their kids. However, a very recent re-analysis of this Mozart-effect has shown that the children DO NOT display greater intelligence (see link below). But can we give people a smart pill and see improvement in their intelligence? Maybe! There is a growing amount of evidence that there are certain types of drugs that improve learning and memory. Most of these types of drugs improve the actions of a neurotransmitter in our brain called acetylcholine (or ACh for short; neurotransmitters are the chemical signals that our neurons use to tell other neurons to do something). Some drugs seem to work through the ACh system to improve our vigilance (or how well we pay attention to details), while others seem to improve our abilities to do certain tasks (like pressing a button when you hear a certain sound). To make a long story short, yes we can give certain drugs and see some improvement - but usually it is an improvement in performance - not intelligence. Moreover, usually these improvements only happen over the short term. If you continue to take the drug you won't continue to see more improvement - in fact, you often will develop worse performance. So, right now, no we can't really improve our intelligence. But 25 years from now (when maybe you have children, or when you are researching this question) the answer might be different! Thanks for a great question. I hope this helps shed some light on the issue for you. Josh Rodefer, Ph.D. Harvard Medical School INTERESTING LINKS: The I.Q. gene? Time magazine cover story from Sept 13, 1999 The Mozart Effect Mozart Effect Hits Sour Notes (Harvard newspaper article) Kaplan Test Preparation Courses International Society for Twin Studies Performance Enhancing Drugs and Athletics, by Jennifer Wolff Article in JAMA about the drug Mark McGwire was taking
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