The Genius in All of Us: New Insights Into Genetics, Talent, and IQ (45 page)

Read The Genius in All of Us: New Insights Into Genetics, Talent, and IQ Online

Authors: David Shenk

Tags: #Psychology, #Cognitive Psychology & Cognition, #Cognitive Psychology

Commenting on this Wolff article on his Web site, Malcolm Gladwell writes:

We’ve always known that running is culturally important in Kenya, in a way it isn’t anywhere else in the world. But these are staggering numbers. A
million
10 to 17 year olds running
10 to 12
miles a day? I’m guessing the United States doesn’t have more than 5,000 or so boys in that age bracket logging that kind of mileage. [Seventy] miles a week is an enormous amount of running—even for an adult. I ran middle distance at a nationally competitive level as a teenager, and never got close to 70 miles a week.

I know this isn’t going to put the genetic argument about Kenyan running dominance to rest. But maybe it should. It’s a far more parsimonious explanation. No one ever claims that Canadians are genetically superior to everyone else when it comes to hockey, or that Dominicans have a genetic advantage when it comes to baseball. We all accept the fact that those two countries succeed at those sports because they draw their elite talent from a developmental pool that is simply larger—in relative and in some cases absolute terms—[than] other nations. [It’s] a numbers game. If Kenya really has a million kids, doing that kind of mileage, then we scarcely need any other explanation for their success.

Here’s the appropriate thought experiment. Imagine that every year 50 percent of all American 10 year old boys were shipped to Boulder, Colorado, where they ran 50 to 70 miles a week at altitude for the next seven years. Would the United States regain control of international middle and long distance running? (Gladwell, “Kenyan Runners.”)

    
High-altitude training and mild year-round climate are critical
:

Sir Roger Bannister’s statement, that it would take a lifetime for an athlete born at sea level to adapt for maximum exercise at medium altitude, was proved correct. (Noakes, “Improving Athletic Performance or Promoting Health through Physical Activity.”)

    
In testing, psychologists discovered a particularly strong cultural “achievement orientation
”:
Hamilton, “East African running dominance,” pp. 391–94.

   Much research has been conducted on individuals “high in achievement motivation” (HAMs). In 1938, H. A. Murray defined HAMs as those who seek challenge, desire to attain competence, and strive to outdo others.

Psychologists John M. Tauer and Judith M. Harackiewicz write:

Our results provide strong evidence that the effects of competition on intrinsic motivation are moderated by achievement orientation, even when feedback is not provided. Our findings converge with those of Study 1 to suggest that HAMs and LAMs [individuals low in achievement motivation] respond to competition very differently …

Clearly, positive feedback is not the reason HAMs enjoy activities in competition. In Study 1, HAMs enjoyed Boggle more in competition than LAMs, even when they received negative feedback. In Study 2, we observed similar reactions in the absence of any outcome feedback. Taken together, these results clearly demonstrate that the differential effects of competition are due to the competitive context established at the beginning of competition …

The results of this study are therefore consistent with Joe Paterno’s claim that competition can be enjoyable regardless of whether one wins or loses. (Tauer and Harackiewicz, “Winning isn’t everything,” pp. 209–38.)

    
How can the rest of the world defuse Kenyan running superiority? Answer: Buy them school buses
:
Wolff, “No Finish Line.”

    
“coaches in Kenya can train their athletes to the outer limits of endurance
”:
Wolff, “No Finish Line.”

    
And what of genetics? Are Kenyans the possessors of rare endurance genes, as some insist? No one can yet know for sure, but the new understanding of GxE and some emergent truths in genetic testing strongly suggest otherwise
.

Some pertinent comments on this from T. D. Brutsaert and E. J. Parra:

First, the cumulative evidence, going back more than one century, is all but overwhelming in support of the general idea that genes are responsible for some of the variation in human athletic performance.

The second point is that despite the obvious role of genetics in human physical performance, there is little unequivocal evidence in support of a specific genetic variant with a major gene effect on a relevant performance phenotype.

Much like the complex genetic and environmental etiology of chronic disease, athletes likely emerge on a predisposing and favorable genetic background where individual alleles are both common and have only modest effects.

The challenge for exercise science is to incorporate an even broader concept of the environment to include environmental influences that act, not just over the short term, but during critical periods of development including prenatal life, early childhood, and adolescence. (Brutsaert and Parra, “What makes a champion?” p. 110.)

    
Skin color is a great deceiver; actual genetic differences between ethnic and geographic groups are very, very limited
.

According to researchers at the National Human Genome Research Institute:

A prominent exception to the common distribution of physical characteristics within and among groups is skin color. Approximately 10% of the variance in skin color occurs within groups, and ∼90% occurs between groups (Relethford 2002). This distribution of skin color and its geographic patterning—with people whose ancestors lived predominantly near the equator having darker skin than those with ancestors who lived predominantly in higher latitudes—indicate that this attribute has been under strong selective pressure. (Berg et al., “The use of racial, ethnic, and ancestral categories in human genetics research,” pp. 519–32.)

    
All human beings are descended from the same African ancestors
.

Kate Berg writes:

The existing fossil evidence suggests that anatomically modern humans evolved in Africa, within the last ∼200,000 years, from a pre-existing population of humans (Klein 1999). Although it is not easy to define “anatomically modern” in a way that encompasses all living humans and excludes all archaic humans (Lieberman et al. 2002), the generally agreed-upon physical characteristics of anatomical modernity include a high rounded skull, facial retraction, and a light and gracile, as opposed to heavy and robust, skeleton (Lahr 1996). Early fossils with these characteristics have been found in eastern Africa and have been dated to ∼160,000–200,000 years ago (White et al. 2003; McDougall et al. 2005). At that time, the population of anatomically modern humans appears to have been small and localized (Harpending et al. 1998). Much larger populations of archaic humans lived elsewhere in the Old World, including the Neanderthals in Europe and an earlier species of humans,
Homo erectus
, in Asia (Swisher et al. 1994).

Fossils of the earliest anatomically modern humans found outside Africa are from two sites in the Middle East and date to a period of relative global warmth, ∼100,000 years ago, though this region was reinhabited by Neanderthals in later millennia as the climate in the northern hemisphere again cooled (Lahr and Foley 1998). Groups of anatomically modern humans appear to have moved outside Africa permanently sometime >60,000 years ago. One of the earliest modern skeletons found outside Africa is from Australia
and has been dated to ∼42,000 years ago (Bowler et al. 2003), although studies of environmental changes in Australia argue for the presence of modern humans in Australia >55,000 years ago (Miller et al. 1999). To date, the earliest anatomically modern skeleton discovered from Europe comes from the Carpathian Mountains of Romania and is dated to 34,000–36,000 years ago (Trinkaus et al. 2003). (Berg et al., “The use of racial, ethnic, and ancestral categories in human genetics research,” pp. 519–32.)

    
there is roughly ten times more genetic variation within large populations than there is between populations
.

   Moreover, genetic variation is even higher inside Africa than it is elsewhere. The following data are according to researchers at the National Human Genome Research Institute:

In general, however, 5–15% of genetic variation occurs between large groups living on different continents, with the remaining majority of the variation occurring within such groups (Lewontin 1972; Jorde et al. 2000a; Hinds et al. 2005) …

For example, ∼90% of the variation in human head shapes occurs within every human group, and ∼10% separates groups, with a greater variability of head shape among individuals with recent African ancestors (Relethford 2002).

In addition to having higher levels of genetic diversity, populations in Africa tend to have lower amounts of linkage disequilibrium than do populations outside Africa. (Berg et al., “The use of racial, ethnic, and ancestral categories in human genetics research,” pp. 519–32.)

It has also been determined that human beings are far less different from one another than other animals are within their own species:

The data gathered to date suggest that human variation exhibits several distinctive characteristics. First, compared with many other mammalian species, humans are genetically less diverse [than other species]. (Berg et al., “The use of racial, ethnic, and ancestral categories in human genetics research,” pp. 519–32.)

    
“While ancestry is a useful way to classify species
”:
Wilkins, “Races, Geography, and Genetic Clusters.”

    
By no stretch of the imagination, then, does any ethnicity or region have an exclusive lock on a particular body type or secret high-performance gene
.
Body shapes, muscle fiber types, etc., are actually quite varied and scattered, and true athletic potential is widespread and plentiful.

   Even Jon Entine acknowledges this. Bob Young writes:

Entine is careful to stress that he’s talking about trends among groups of very elite athletes. He’s not saying white guys should give up playing pickup ball because they can’t jump. He is saying that among the small population of elite athletes, there are differences that could give a fraction-of-a-second advantage to people of African ancestry, which makes the difference, at the elite level, between a medal and fourth place …

In the end, Entine says, the individual’s work ethic, competitive spirit and training remain the key to success. “That’s why plenty of guys with Scottie Pippen’s talent are [stuck] in the CBA [Continental Basketball Association],” he says. (Young, “The Taboo of Blacks in Sports.”)

    
In the words of King’s College’s developmental psychopathologist Michael Rutter, genes are “probabilistic rather than deterministic
”:
Rutter, Moffitt, and Caspi, “Gene-environment interplay and psychopathology,” pp. 226–61.

   For my critique of the term “probabilistic,” see the note “Many scientists have understood this much more complicated truth for years but have had trouble explaining it to the general public. It is, after all, a lot harder to explain and understand than simple genetic determinism” on page 151.

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