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Human Intelligence: Expert Q&A

Neurologist Fred Lepore answers questions ranging from what IQ measures, to the shape of Einstein's brain, to neural plasticity. If your question wasn't answered here, try watching the NOVA scienceNOW program, "How Smart Can We Get?"  


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Q: Is it true that when Einstein's brain was inspected he was missing part of what is usually found in the brain? If so, what part of the brain is this, and what is its function? Is this the reason for Einstein's genius? Ethan Tucker, Cleveland, OH

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Fred Lepore: Einstein's brain had no missing parts. Prior research published in 1999 proposed that Einstein had enlarged parietal lobes. A more definitive study of the neuroanatomical differences of Einstein's brain will be published by Dean Falk, Adrianne Noe, and myself in November.

Q: I truly believe that creativity enables intelligence. Along those lines, is there any evidence that higher IQ brains have more numerous, more diverse connections? And, is making these connections a skill that can be practiced/learned? Justin Hargrove, Altus, OK

Lepore: You have pinpointed a cutting-edge area of brain research, which studies the neural connections—axons and dendrites in the brain's white matter. We are using Diffusion Tensor Imaging to study the brain's "connectome." (S. Seung, 2012) That said, I am unaware of neuro-anatomic studies that show more or different connections in higher IQ brains, but I believe they will be found. Any mental stimulus or task, from writing a grocery list to studying quantum mechanics, will rewire neural connections. I don't think there is a "one best" approach to making or re-making neural connections.

Q: I understand Einstein had a parietal lobe 15 percent wider than normal. I am wondering, have any studies been done on great poets and did they exhibit a part of the brain that was wider than normal? Thanks. Arnold Robbins, Novato, CA

Lepore: With the exception of a superficial study of Walt Whitman's brain, which was "dropped on the floor by a careless assistant," (Spitzka, 1907) we know a whole lot more about "The Lives of the Poets" than their brain anatomy. Although Whitman's brain "contained multitudes," as he wrote, it was smaller than average.

Q: Has anything been discovered about people with superhuman brain abilities who are also normal people (like Marilu Henner with her super memory?) Rick Goulet, Herndon,

Lepore: We don't really know where long-term memories are stored in the brain. Short-term memory acquisition occurs in the temporal lobes and hippocampi, but I don't believe that mnemomists, also known as memory savants, have bigger temporal lobes. Surprisingly, increased functional MRI activity has been demonstrated in the frontal lobes of mnemonists engaged in memory tasks.

Q: What happens within the brain as it ages that results in memory loss, slower thinking, and other changes, and why are some people more mentally affected by aging then others? Dominic, Westport, CT

Lepore: When we see patients, neurologists are frequently trying to determine if the patient has "benign forgetfulness" of aging or a neurological disease such as Alzheimer's Disease. It can be a difficult distinction for even the most savvy clinician. For all of us with aging brains, the bad news is that we lose neurons but the good news is that we're born with surplus neurons and the remaining neurons have the compensatory capacity to "re-wire," also known as neural plasticity.

Q: What is the connection between mirror neurons and more intelligent people? Particularly in students because they see, then do, in a controlled environment. Tommy Card, Long Island, NY

Lepore: Mirror neurons—originally discovered in premotor cortex of monkeys—fire during execution of goal-directed motor acts and during the observation of motor acts. Theories abound as to the purpose of mirror neurons in humans. They may underlie learning through imitation, empathy, self-awareness, and transmission of culture (Ramachandran, 2007.) The link between intelligence and mirror neurons remains to be demonstrated. Rizzolatti, one of the discoverers of mirror neurons, has speculated that mirror neuron dysfunction may be implicated in autism spectrum disorder.

Q: Are there exercises we should be doing with young minds that will create beneficial scaffolds for future brain health? Peter, CT

Lepore: I don't think that clinical neuroscience can identify the best kind of early education. Any intellectual exercise—including the "Three R's"—facilitates forming neural connections. In 2012 the "best education" can't be determined with neuro-imaging studies. I suspect that the earlier we start educating children, e.g. pre-school, the better. But my assertion is based on talking with my wife, who is a teacher, and not on my neuroscientific background.

Q: Can the brain regenerate pathways and neurons even later in life to enhance one's intelligence? Sohrob Tahmasebi, San Diego, CA

Lepore: Neuronal regeneration can occur to a very limited extent in normal and injured brains. Rewiring of neural pathways is taking place constantly in both normal and injured brains. This neural plasticity very probably changes or improves cognition. If you believe that we are "smarter" when we learn a new skill, the neural basis of that new skill and increased "smarts" is probably change in neural connectivity. Or, as we say in neuroscience, "Neurons that fire together, wire together."

Q: Can I reprogram my brain to unblock my genius? Are humans all geniuses but most people have formed neural pathways that block their natural childlike ability to achieve extraordinary feats? Luke Derror, Bremerton, WA

Lepore: Continuing education and mental stimulation is the only way I know to "reprogram, " or at least "rewire," your brain. Are we all born as geniuses, and then some of us "get dumb?" Or are only a few people born with a brain that has the capacity for genius? Given normal patterns of biological distribution, I suspect some people are born with "higher performing" brains and others with "lower performing" brains. But what measuring stick should we use? Some people can master calculus in their early teens but are at a loss in understanding a poem. The sheer variety of human intellectual attainment is bewildering, and the level of functioning of different mental capacities in the same person may not be uniform.

Q: In the book "The Brain That Changes Itself," the author describes a computerized tool (Fast Forward) that significantly helps children learn and develop. Do you believe such tools are effective? Clay Creasey, NJ

Lepore: Whether education is analog (a teacher in the classroom) or digital (a software teaching program) is not critical. However it is accomplished, successful learning will enhance neural connectivity in "children of all ages." As a neurologist, and not a teacher, I don't know of a best teaching methodology or software shortcut to optimal learning.

Q: What is the IQ test looking for really? "Intelligence" isn't good enough. What part of "intelligence" does it measure? How fast you are? Or how much data you can process at once? Or something else? B. Duncan, NY

Lepore: IQ subtests measure a variety of cognitive skills. If the subtests highly correlate with each other, they may provide a measure of general intelligence or g. The question is complicated by the existence of multiple intelligences (Howard Gardner) and the limitations of IQ tests. The average scores on IQ tests have greatly increased over the years. Does this mean that our brains are bigger and better than the brains of our ancestors? Probably not (Flynn, 2012.)

Q: A study recently found that brushing one's teeth can prevent dementia due to a steady cleaning away of oral bacteria. Einstein's brain was found to be lacking detrimental bacteria. What role do microorganisms play in a person's mental ability? Rob Smat, Fort Worth, TX

Lepore: There is no published data regarding bacteria and Einstein's brain. All brains are normally sterile. If they are not sterile, the individual has meningitis or encephalitis. Clearly bacterial, prion, treponemal, viral, fungal, protozoan, etc. infections of the brain and meninges will cause impairment of brain function.

Q: Would you rather lose functional use of your amygdala or pre-frontal cortex? J. Chuen, Houston, TX

Lepore: Humans who lose both amygdalas develop Kluver-Bucy syndrome, characterized by hyperorality, hypersexuality, and blunted emotions. Pre-frontal cortex loss can present with personality changes, apathy, disinhibition of behavior, urinary incontinence, impaired gait, etc. These are profound changes of the human condition, and I have no stated preference.

Q: A recent study found that working memory assessed at age 5 was a better predictor of future academic success than IQ. What are the implications of this and is IQ an approximation of working memory? Do both constructs utilize the same brain networks? Eric Garrett, United States

Lepore: Working memory is understandably crucial to academic success. In order to manipulate concepts, the working memory has to provide ready access to facts and concepts. Following this line of reasoning, the person with the best memory should be an outstanding genius. Not so. Read "Luria's Mind of the Mnemonist," which compellingly describes the average (at best) intellectual attainments of a man with a truly phenomenal memory. Memory circuits include the arcuate fasciculus, medial temporal lobe/hippocampi, and poorly localized cortical regions (for long-term memories.) There is no discrete "IQ brain network." My guess is that IQ is globally represented in the brain.

Q: Do you have an opinion on what happens to all that intellectual information/data in a brain after we die? Thanks. Cathy Woinski, Lewes, DE

Lepore: Neurophilosophy advises that the mind (or soul)-brain question you pose can be answered in two ways:

1. According to materialism, when the brain dies the mind/soul/ "intellectual information" is irrevocably lost.

2. According to dualism, the mind/soul/"intellectual information" is separate from the brain and persists despite the death of the brain.

Most neuroscientists would endorse materialism as their working hypothesis. I remain undecided because neuroscience is as yet unable to solve neurophilosophy's so-called Hard Problem: How does brain tissue produce subjective experience? Lacking a solution to the Hard Problem, what happens to the mind/soul/"intellectual information" with the death of the brain remains a Big Question for me.

Q: What is it that makes someone "smarter" than someone else? Is it simply IQ or is there more to it? Aidan Fehr, Calgary, Alberta

Lepore: IQ subtests are measurements of various aspects of intelligence. However there are multiple "intelligences" which may not all be measured by IQ tests. For instance, I'm not sure how well a creative genius such as Picasso would score on conventional IQ tests.

Q: Is there an agreed on definition of intelligence? Mike, Maryville, IL

Lepore: There are multiple "intelligences" such as spatial, linguistic, logical-mathematical, bodily-kinesthetic, musical, interpersonal, intrapersonal, and naturalistic. (Howard Gardner, 1983.) I like James Flynn's definition, which points at "mental abilities that allow us to better deal with the complexity of the modern world."

Q: If we missed some developmental skill in our childhood can we achieve it later in life? Math skills...abstract thinking... Maria M Villegas, GA

Lepore: I do think we can learn skills later in life. It can be difficult but worth the effort. You really can teach "an old dog new tricks," but temper your enthusiasm with realism. Chances are that if you learn a new language after age 10, you will always speak it with a slight accent. In my case it sounds like "parleee vooo Franzaay."

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