Conceptualizations of the factors affecting skill acquisition and the demonstration of expertise generally reflect qualities associated with biological factors such as genes (nature) or those related to environmental or experiential factors such as training and coaching (nurture).
Although the conceptualization of the nature versus nurture debate can be traced at least to Platonic and Aristotelian discussions of human nature in ancient Greece, more contemporary discussions usually start with Francis Galton’s 1874 English Men of Science: Their Nature and Their Nurture; Galton may have taken his title from Shakespeare’s The Tempest (Act 4.1)—“a born devil, on whose nature Nurture can never stick.” Galton’s approach was very clearly influenced by the work of his cousin, Charles Darwin, and focused on the stable, biological factors that are transferred from one generation to the next (known as heritability, the proportion of variance in a population attributed to genetic factors). Alternately, some researchers see human development as starting from a blank slate (tabula rasa) with no innate traits or characteristics, and that all forms of learning and behavior result from interactions with our environment. This extreme nurture viewpoint is demonstrated by behaviorist John B. Watson’s famous boast:
Give me a dozen healthy infants . . . and my own specified world to bring them up in, and I’ll guarantee to take any one at random and train him to become any type of specialist I might select— doctor, lawyer, artist . . . regardless of his talents, penchants, tendencies, abilities, vocations and race of his ancestors. (1998, p. 82)
The history of this debate in psychology is marked by radical shifts in opinion, usually driven by social and cultural factors. For example, after World War II, political and intellectual thought changed to reflect the perspective that differences between individuals resulted from opportunities and experience. This perspective was deemed more socially acceptable than ideologies that sought to separate individuals on the basis of biology since this latter approach was so strongly associate with Nazism. A similar social change occurred in 2001, after the publication of the human genome when researchers advanced positions based on the ultimate power of biology for understanding interindividual differences. James Watson, codiscoverer of the structure of DNA and a key developer of the Human Genome Project, said, “We used to think our future was in the stars. Now we know it is in our genes.” More recently, we have seen a change in direction, at least in some fields of psychology and education, as researchers focus on the solitary role of deliberate practice (a nurture-related variable) in creating the expert performer. The role of nature and nurture factors in sport and exercise is reviewed as follows.
Nature determinants focus on stable biological factors. Each person is the product of a unique sequence of genetic material, half coming from one’s mother and the other half from one’s father in the form of chromosomes. This genetic material (DNA, or deoxyribonucleic acid) is made up of a combination of four chemical bases—adenine, thymine, guanine, and cytosine (abbreviated A, T, G, and C), which group together into base pairs (A with T and G with C) and links of these base pairs form discrete sequences of DNA called genes. Each gene corresponds to a specific biological outcome; for example, the COL5A1 gene found in humans on chromosome 9, encodes for a specific collagen protein relevant to flexibility of ligaments and tendons. Within the normal population, there are multiple variants of this gene, which produces the variability seen across a population. This variability results from different alleles (a variant in the gene sequence) and is known as a polymorphism (the occurrence of many forms of a given gene). Your individual collection of genes (estimated to be between 20,000 and 25,000 genes containing about 3 billion base pairs) is referred to as your genotype.
There is strong evidence that genotypic features affect health, fitness, and performance outcomes. For instance, using both heritability statistics and individual genetic markers, data from the HERITAGE Family Study have shown that specific genotypes are better suited for aerobic activities. Since the publication of the human genome in 2001, hundreds of genes and polymorphisms related either directly or indirectly to performance and fitness phenotypes have been identified. Some of these candidates include the COL5A1 gene mentioned earlier as well as genes for the cardiovascular catalyst angiotensin-converting enzyme (ACE), and the skeletal muscle protein alpha-actin type 3 (ACTN3), which have had varying degrees of success explaining interindividual differences in performance. Moreover, despite the considerable attention given to the search for individual genes responsible for athletic achievement, the manifestation of any biological or psychological effect is likely the result of a complex interaction of thousands of genes, and as a result, identification of individual genes that account for meaningful variation in sportor exercise-related outcomes is extremely difficult.
Few researchers dispute the important role of the environment (nurture) in determining health and fitness related outcomes. In the social and behavioral sciences, few relationships are as robust as the one between practice and achievement. The power law of practice is a mathematical model of this relationship whereby improvements occur quite rapidly at the onset of practice but become more difficult to obtain (requiring greater practice) as the performer becomes more skillful. This law (or derivations of it) has been widely applied and is proposed to describe human learning of perceptual–motor skills ranging from learning to roll cigars and reading text upside down, to scoring a layup in basketball or hitting a bull’s-eye in darts.
Studies from the field of human expertise and expert performance have also supported the relationship between training and ultimate achievement. For example, the proposition of deliberate practice, developed by psychologist Anders Ericsson, is based on the notion that proper training (deliberate practice) performed at the appropriate period of biological and cognitive development is a necessity for the acquisition of expertise in any domain, including sports. Ericsson’s (1996) extensive work on the acquisition of expert performance has shown that an individual’s level of performance in any domain is determined by the amount of time spent performing “a well- defined task with an appropriate difficulty level for the particular individual, informative feedback, and opportunities for repetition and correction of errors” (pp. 20–21).
In addition to the primacy of practice or training to explaining human achievement in sport, other environmental factors are important. For example, Joseph Baker and Sean Horton proposed a number of secondary factors that facilitate the acquisition of appropriate training and practice, including obvious factors like access to proper coaches and having supportive parents, as well as less obvious factors, such as growing up in talent hotbeds or being born at the right time of year to take advantage of relative age effects.
Interactions of Nature and Nurture
Although discussions in sport and exercise psychology generally focus on nurture-related factors, it is clear that most health, fitness, and performance outcomes result from both nature and nurture. Perhaps the clearest example of nature– nurture interaction (or gene x environment interaction) comes from medicine and relates to the condition phenylketonuria (PKU). This genetic disorder causes brain damage and progressive mental retardation in 100% of individuals with the genetic marker for this condition; however, PKU is highly treatable if individuals eliminate phenylalanine from their diet. In this example, a quality with perfect heritability (PKU) is not expressed because of an environmental manipulation (dietary change). Importantly, the DNA that causes this condition remains unchanged; the individual simply does not express the PKU condition. Although examinations of gene x environment interactions are rarely examined in sport and exercise psychology, it is likely that similar effects occur. For example, the COL5A1 gene, by affecting injury risk, likely constrains the amount and intensity of training individuals in certain sports (e.g., sprinting) can perform throughout their development.
Most evolutionary psychologists and geneticists have moved away from the nature–nurture conceptualization on the basis that it is too limited to explain the nuances of the interactions that occur throughout human development. As a result, researchers have developed more comprehensive models of these relationships. For example, dynamic systems theory presumes that human behavior is best seen as the interaction of different systems (biologic, social, psychological) with development being emergent, nonlinear and multi-determined. From this theoretical standpoint, genetic diversity is responsible for some variability in the differences between individuals in how they respond to different experiences and beneficial changes like performance adaptations happen when there is a favorable interaction with important environmental constraints. For example, there is growing consensus in the study of human obesity that the contribution of genetic factors is exacerbated in North American environments that are high in caloric availability.
In evolutionary psychology, focus is on the differences between obligate and facultative adaptations. Obligate adaptations occur no matter what environment a person experiences while facultative adaptations are sensitive to environmental variations. The fact that sugar tastes sweet and lemons taste sour (obligate adaptations) does not change if they are experienced in a different environment. Other, more complex qualities reflect facultative adaptations, similar to if–then statements. The attachment style one has as an adult (i.e., how you approach long-term relationships), for example, is affected by the level of trust one had in their caregivers as a child. If a young person often has promises broken by a parent, this may lead to trust issues as an adult. Given that obligate adaptations do not typically vary across development, scientists in this area focus on how different developmental experiences affect the expression of facultative adaptations.
Another important element in this discussion relates to the emerging concept of epigenetics, which shows that changes in gene expression can occur through modifications to the genome that do not involve a change in the underlying DNA sequence. This field of research suggests that experiences provide a stimulus for genes to be turned on or off. For example, a Swedish study showed that a single hard workout resulted in genes involved in energy metabolism being switched on, with harder work resulting in a stronger effect.
Collectively, research on the effects of biology and experience on human behavior and performance indicate that the nature versus nurture dichotomy is ineffective for explaining the dynamics of how these factors interact and the complexity of this process.
- Baker, J., & Davids, K. W. (2007). Sound and fury, signifying nothing? Future directions in the naturenurture debate. International Journal of Sport Psychology, 38, 135–143.
- Baker, J., & Horton, S. (2004). A review of primary and secondary influences on sport expertise. High Ability Studies, 15, 211–228.
- Carlsson, S., Andersson, T., Lichtenstein, P., Michaëlsson, K., & Ahlbom, A. (2006). Genetic effects on physical activity: Results from the Swedish twin registry. Medicine and Science in Sports and Exercise, 38, 1396–1401.
- Davids, K. W., & Baker, J. (2007). Genes, environment and sport performance: Why the nature-nurture dualism is no longer relevant. Sports Medicine, 37, 961–980.
- Davids, K. W., Button, C., & Bennett, S. J. (2008). Dynamics of skill acquisition: A constraints-led approach. Champaign, IL: Human Kinetics.
- Ericsson, K. A. (Ed.). (1996). The road to excellence. The acquisition of expert performance in the arts and sciences, sports and games. Mahwah, NJ: Erlbaum.
- Ericsson, K. A. (2007). Deliberate practice and the modifiability of body and mind: Toward a science of the structure and acquisition of expert and elite performance. International Journal of Sport Psychology, 38, 4–34.
- Klissouras, V. Geladas, N., & Koskolou, M. (2007). Nature prevails over nurture. International Journal of Sport Psychology, 38, 35–67.
- Pinker, S. J. (2002). The blank slate: The modern denial of human nature. New York: Viking Press.
- Watson, J. B. (1998). Behaviorism. New Brunswick, NJ: Transaction. (Original work published 1924)