Just How Smart Am I?

Q. How so?

A. What they have shown recently is that it’s hard to find a trait, a simple or complex trait in humans that doesn’t have significant genetic influence. You can’t make that blanket statement that people did 25 years ago that genes had no influence on intelligence or talent.

Q. OK ...

A. But the problem is that then they take it way, way beyond that. They’re actually looking at these statistical numbers and saying, for example, 60 percent of intelligence is genetic. That’s like saying 60 percent of Shakespeare’s brilliance comes from adjectives. You can’t separate out other influences. That’s not the way biology works.

Q. Because twins, especially by the time they’re adults, won’t necessarily have had the same influences or opportunities?

A. Right. You can’t say what an individual is capable of because you don’t know until he finds himself in the right circumstances, regardless of ability. If the stars align, there’s no telling what is possible.

Q. Even for someone older? Say a 50-year-old wanted to start playing the piano.

A. It’s tougher. But the brain is still plastic at 50 and there are still muscles to build there. If anything, the science is stronger in that regard.

Q. What advantage might age give you?

A. I don’t think it makes the hard work any easier in terms of practicing. But in terms of making intelligent judgment, you have a lot more perception about what you need to do, what you don’t, what’s important and what’s not. Music is a great example. Unless you’ve lived in a cave, your ear is a lot better. Also with the creative arts and scientific endeavors, the wisdom and experience component is a powerful one.

Q. How have our IQ scores influenced our views on intelligence?

A. I think you could make the case that the current over-50 crowd has been a primary victim of the ideology that the IQ test is an insight into your fixed, innate intelligence. That became the central ideology of intelligence for the entire 20th century. And once you grow up with a certain idea of what you’re made of, how smart you are, it becomes fundamental to you.

Q. What, then, does an IQ test measure?

A. It measures your current academic abilities, and it does a good job of doing that. The IQ tests are well produced and measure abstract reasoning and assorted academic abilities, which are skills that people have accrued up to the point they are tested.

Q. Why have IQ scores risen over the last century?

A. We’re thinking better. More than 100 years ago, there wasn’t a heck of a lot of abstract thought. There were intellectuals that could think abstractly, but the common parlance didn’t include phrases and concepts that were strong on abstract thought. Over time, we actually have become a more intellectual culture.

Q. What is talent?

A. Any ability is a process that involves building up skills. And we have to have the resources, right attitude, lots of things have to come together. They often don’t, even if the desire is there.

Q. And time?

A. A big factor. You have to have lots of it. Some people simply can’t afford that.

Q. The Bell Curve made quite a controversial splash in 1994, proposing that some groups of people have missed out on the genetic lottery and will never be as smart as others.

A. It’s no accident that the people they talked about with inferior genes actually have lived in horrible circumstances and have not had the chance to tap into their potential the way that those who’ve had economic and cultural advantages have had. The signs are very strong that that potential is quite extraordinary in most of us, if we can apply the resources. The idea that we’re kind of two or more separate classes of human beings is not scientifically correct.

Q. No superior genes?

A. We can’t say at this point that there aren’t genes that you’d rather have. We don’t know yet. But no genes are genetic islands. They really don’t produce stuff on their own.

Q. Can genes also be altered?

A. Genes can’t be altered except by random mutation, but what can be altered is the coding around the genes—the epigenome, which is critical in gene expression and in helping figure out when the genes are going to get turned on and off and how often.

Not only do we alter the expression of our genes by changing our epigenome by our actions—the food we eat and the lives we lead—but we usually pass on those changes to our kids and even on to subsequent generations.

Q. Your lifestyle choices can be transferred to your children … on a genetic level?

A. Everything you do in your life can have an influence on gene expression. Absolutely everything. That’s why it’s so complicated. It’s never going to boil down to a simple formula.

Q. For example?

A. Say a drug could be carcinogenic and a lot of people exposed to it end up getting cancer. Cancer results from genetic expression. Those genes are being expressed as a result of certain types of chemicals. That’s why some people can have exactly the same gene and, depending on environmental exposure to certain things, one person might get cancer and another won’t.

Q. But this can be passed on?

A. You could be passing down a lot of byproducts without even realizing it. It looks like leading a balanced life with making good decisions on every level, even intellectually, all could have an effect on how your kids’ genes and their kids’ genes are expressed.

There are so many reasons to lead a healthy life, and here’s another one: You could be determining the fate of your grandchildren.

Q. No pressure.

A. Exactly. Think about picking up that cigarette at age 16! I wouldn’t be surprised if we start seeing ads—it’s going to take a little while to filter down—the American Cancer Society would be perfectly within its right to say hey, if you’re a teenager smoking, you’re not only affecting your own life but any kids and grandkids that are coming down the road. Not that a lot of teens think of that stuff.

Carol Kaufmann is a contributing editor at the AARP Bulletin.