The Principle Difference of Approaches: Toward a Dynamic Model of Biological and Environmental Influence in Personality Development
Although remnants of the blank slate perspective still permeate both academic and popular discourse, substantial empirical evidence clearly indicates that 50-60% of the variance in personality traits—such as openness, conscientiousness, and general mental ability (GMA) — is biologically determined (Polderman et al., 2015; Bouchard & McGue, 2003). Yet, to my ongoing astonishment, many contemporary thinkers continue to lean toward environmental determinism or blank slate-like models, despite the growing empirical consensus that emphasizes the predominant role of biological influence.
The Overseen Mechanics: Beyond the Nature vs. Nurture Dichotomy
Much of the ongoing discourse surrounding personality development has been shaped by a misleading dichotomy: biology versus environment. As Steven Pinker (2002) explains in The Blank Slate, human development is not a simple contest between innate tendencies and external influences. Rather, it is a dynamic interplay where biology shapes and channels how individuals respond to their environments.
Pinker critiques this oversimplified opposition, highlighting that biology does not act in isolation but establishes a framework — defining both constraints and potentials — within which environmental triggers and learning processes operate. Drawing from historical thinkers, Pinker reminds us that even Rousseau and Hobbes, despite their opposing moral evaluations of human nature, both recognized that human behavior is grounded in biological predispositions shaped by evolutionary forces.
This thesis is further supported by contemporary research, which consistently demonstrates that human traits emerge through a continuous interaction between genetic inheritance and socio-cultural factors. It is this mutual reinforcement — rather than nature or nurture acting alone — that drives personality and psychological development.
At SelfFusion, we fully align with Pinker’s conclusion: “It is not nature versus nurture but nature via nurture.”
We Align with Construction Theory
At SelfFusion, we adopt an approach informed by niche construction theory (Laland et al., 2000), which enables us to move beyond the outdated separation of nature and nurture. Niche construction theory posits that organisms are not merely passive recipients of environmental pressures but active agents that modify their environments. These modifications, in turn, shape the selection pressures they and their descendants experience.
In the human context, this means that socio-cultural ecosystems—ranging from societal structures to family systems and work environments—exert enduring selective forces that mold the evolution of psychological traits over time. In this sense, culture itself is an evolutionary force that interacts with biological predispositions, gradually reinforcing certain traits such as cooperation, assertiveness, or resilience depending on environmental demands.
Recent research by Odling-Smee, Laland, and Feldman (2003) also supports this view, emphasizing that niche construction plays a key role in shaping the developmental trajectories of individuals and populations, reinforcing that our biology is both a product and a shaper of environmental pressures.
However, when addressing the development of a specific individual, we at SelfFusion take this concept even further. While niche construction theory accounts for evolutionary pressures over generations, we extend this understanding into how individuals, within their lifetime, dynamically co-create meaning and personal adaptation through their structured internal value hierarchies (SIVHs) — a concept we will explore in detail in the following sections of this article.
Larger than Expected Biological Component on the Individual Level
When personality traits are analyzed through a psychometric lens, one of the most significant oversights in blank slate-leaning models is the failure to recognize how environmental inputs are frequently biologically mediated.
Take, for instance, a child’s openness to ideas, a trait closely linked to general mental ability (GMA) and fluid intelligence (DeYoung et al., 2012). This trait is shaped not only by the direct heritability of genes from parents but also by the environment those same parents construct. In other words, both the genetic blueprint and the developmental setting stem from biologically influenced parental traits, carrying profound implications for individual personality development.
While it is well-established that biological heritability accounts for approximately 50%-60% of the variance in traits like openness and GMA (Bouchard & McGue, 2003), the remaining variance is often mischaracterized as simply “environmental.” However, as Scarr & McCartney (1983) demonstrated, environments are often extensions of parental biology. Parents with higher IQs not only transmit advantageous genetic material but also create cognitively enriched settings — illustrating a classic example of a gene-environment correlation.
Further studies by Rowe et al. (1999) and Tucker-Drob & Harden (2012) reinforce this point, showing that children exposed predominantly to the parent with higher GMA are more likely to realize their cognitive potential. The enriched, intellectually stimulating environment created by such parents is not a neutral or purely external factor; it is a biological extension of their own cognitive capacities.
Additionally, recent research in behavioral genetics (Plomin et al., 2016) has further highlighted how gene-environment correlations are pervasive, with parents shaping developmental niches that reflect their own personality profiles and cognitive abilities. This creates a secondary layer of biological influence, where the environment itself serves as an indirect vector of inherited traits.
Primary and Secondary Biological Influence Model
Based on these observations, we posit that a clearer distinction should be made between two distinct layers of biological influence:
Primary Biological Input: This refers to the direct genetic inheritance of general mental ability (GMA) and personality traits from the parents, shaping the child’s foundational cognitive and dispositional profile.
Secondary Biological Input: This encompasses the biologically-informed behaviors, parenting styles, and enriched environments shaped by the parent with higher GMA or more adaptive personality traits. These environments serve to either amplify or inhibit the child’s realization of their genetic potential. In this sense, the environment functions as a biologically influenced extension of the parent.
Implications
This two-tiered model aligns with and expands upon Bronfenbrenner’s ecological systems theory (1979), which highlights the significant influence of microsystems — such as the family unit — on human development. Furthermore, it resonates with dynamic systems theory (Thelen & Smith, 1994), which emphasizes that development is not a linear process but emerges from a continuous and reciprocal interaction between biological predispositions and environmental affordances.
By introducing the distinction between primary and secondary biological inputs, we further bridge the gap between biological inheritance and environmental construction, illustrating how both operate synergistically to shape individual development.
Relation with SIVHs
How do Structured Internal Value Hierarchies (SIVHs) integrate into this model? The connection is profound. When the parent with higher general mental ability (GMA) consciously recognizes their pivotal role in shaping the child’s development — particularly during the critical window from approximately ages 4 to 16 — their influence is greatly magnified.
A parent equipped with a well-formed SIVH, grounded in principles such as truthfulness, responsibility, and the pursuit of personal potential, is more likely to act intentionally and consistently in the child’s intellectual and emotional development. The SIVH serves as a guiding internal compass, ensuring that the parent’s actions align with higher-order goals related to fostering the child’s cognitive and moral growth.
In this way, the SIVH does not merely enhance parenting practices—it becomes the mechanism through which the parent transforms their secondary biological input into an active, values-driven force. The parent’s structured internal values shape the micro-decisions and habits that ultimately build the child’s intellectual scaffolding, extending beyond simple gene-environment correlations and embedding purposeful meaning into the developmental process.
Conclusion
Ultimately, the development of personality traits — particularly those related to cognition and openness to ideas — cannot be sufficiently explained by a simplistic additive model of biology and environment. Instead, what emerges is a biologically mediated feedback loop where parental influence, specifically through enriched environments and value-driven behaviors, serves as an extension of genetic inheritance.
The secondary biological input — the biologically-informed environment shaped by the cognitively superior parent — is far more than a passive background variable. It becomes an active amplifier or inhibitor of a child's latent potential. Crucially, when this parental influence is channeled through a clearly defined Structured Internal Value Hierarchy (SIVH), its effect is not just magnified but purposefully directed. The SIVH ensures that the parent’s actions are aligned with higher-order values such as truthfulness, responsibility, and personal development, reinforcing the child’s cognitive and emotional growth with intentionality.
This framework provides a novel lens through which to interpret psychometric and developmental data, urging us to move beyond static heritability models. It calls for the recognition that biological legacy operates not only through genes but also through biologically driven environmental scaffolding, deeply intertwined with personal value structures. Understanding this dynamic offers a more sophisticated and actionable perspective on how cognitive and personality outcomes are shaped across generations.
Some of the References Used for the Article
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Bronfenbrenner, U. (1979). The Ecology of Human Development: Experiments by Nature and Design. Harvard University Press.
DeYoung, C. G., Flanders, J., & Peterson, J. B. (2012). Higher-order factors of the Big Five predict fluid intelligence in a culturally diverse sample. Intelligence, 40(2), 109-119.
DeYoung, C. G., Hirsh, J. B., Shane, M. S., Papademetris, X., Rajeevan, N., & Gray, J. R. (2010). Testing predictions from personality neuroscience: Brain structure and the Big Five. Psychological Science, 21(6), 820-828.
Laland, K. N., Odling-Smee, F. J., & Feldman, M. W. (2000). Niche construction, biological evolution, and cultural change. Behavioral and Brain Sciences, 23(1), 131-175.
Odling-Smee, F. J., Laland, K. N., & Feldman, M. W. (2003). Niche Construction: The Neglected Process in Evolution. Princeton University Press.
Pinker, S. (2002). The Blank Slate: The Modern Denial of Human Nature. Viking.
Plomin, R., DeFries, J. C., Knopik, V. S., & Neiderhiser, J. M. (2016). Top 10 replicated findings from behavioral genetics. Perspectives on Psychological Science, 11(1), 3-23.
Polderman, T. J., Benyamin, B., de Leeuw, C. A., Sullivan, P. F., van Bochoven, A., Visscher, P. M., & Posthuma, D. (2015). Meta-analysis of the heritability of human traits based on fifty years of twin studies. Nature Genetics, 47(7), 702-709.
Rowe, D. C., Jacobson, K. C., & Van den Oord, E. J. (1999). Genetic and environmental influences on vocabulary IQ: Parental education level as moderator. Child Development, 70(5), 1151-1162.
Scarr, S., & McCartney, K. (1983). How people make their own environments: A theory of genotype → environment effects. Child Development, 54(2), 424-435.
Thelen, E., & Smith, L. B. (1994). A Dynamic Systems Approach to the Development of Cognition and Action. MIT Press.
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