2000 words

“Genetic determinism can be described as the attribution of the formation of traits to genes, where genes are ascribed more causal power than what scientific consensus suggests” Gerick et al (2017)

Defining hereditarianism and DST

Hereditarianism has many entailments, but a main one is that genes are necessary and sufficient for phenotypes. Hereditarianism can be defined succinctly as: the belief that human traits, behaviors, and capabilities are predominantly or solely caused by genetic inheritance, with the environment being negligible. So this belief implies that genes are necessary (without the specific genes, the trait wouldn’t appear) and sufficient (the genes in question can alone account for the appearance of the trait without significant environmental influence). So if genes are sufficient for phenotypes, then we could predict one’s phenotype from one’s genotype. (It’s also reductionist and deterministic). That a form of genetic determinism is taught in schools (Jamieson and Radick, 2017) is one reason why this hereditarian view must be fought.

But if development is understood as the dynamic interaction between genes, environment, and developmental products where no single factor dominates in the development of an organism (the DST view), then a view that assumes the primacy of one of the developmental resources (hereditarianism and it’s assumption about genes), then this leads to a logical incompatibility and incoherence. Since certain things are true about organismal development, then hereditarianism cannot possibly be true. I have made a similar argument to this before, but I have not formalized it in this way. Since we know that development is context-dependent, and we know that hereditarianism assumes the context-independence of genes, we can rightly assume that hereditarianism is false. Furthermore, since hereditarianism assumes no or negligible developmental plasticity, then that’s another reason to reject it. Here’s the argument:

(1) Hereditarianism (H) implies genetic determinism (GD).
(2) GD implies negligible developmental plasticity (DP).
(3) But DP isn’t negligible.
(C) Therefore H is false.

H=hereditarianism
GD=genetic determinism
D=developmental plasticity/environmental influence

(1) H->GD
(2) GD->¬D
(3) D
(C) ∴¬H

Under the assumption that hereditarianism is a species of genetic determinism, and DST is a context-dependent account of development: If DST is accurate, then hereditarianism is false. We know that traits aren’t genetically determined, so DST is accurate. Therefore, hereditarianism must be false.

Hereditarians have tried paying lip service to the interactionist/developmental systems view (as I showed here and here), but by definition, hereditarianism discounts interactionism since even their main tool (the heritability estimate) assumes no interaction between genes and environment (whereas the interaction between genes and environment is inherent in the DST philosophy).

We know that genes are not sole determinants of phenotypes, but they are one of many interacting developmental resources, which refutes the often unstated assumption that genes are blueprints or recipes for development. Hereditarianism doesn’t and can’t account for the fact that the environment can enable, contain, and alter genetic expression. Therefore, a holistic—and not reductionist—view of development is one we should accept. The hereditarian view of development is clearly untenable.

Below is an argument I’ve constructed that relies on the argument in Noble (2011) for genes as passive causes:

(1) If genes are passive information carriers, then they do not initiate biological processes independently.
(2) Genes do not initiate their own transcription or replication; they react to triggering signals within a biological system.
(3) Therefore, genes are passive information carriers.
(4) If something is a passive information carrier, it cannot be considered an active cause of biological processes.
(5) So if genes are passive information carriers, then genes cannot be considered an active cause of biological processes.

Noble’s biological relativity argument

Hereditarianism assumes a privileged level of causation (genes are the privileged resource of development). But we know—a priori—that there is no privileged level of causation in biological systems (Noble’s 2012 biological relativity argument). So hereditarianism must be false. Here’s the argument:

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We know the biological systems are characterized by multiple interacting levels molecular, cellular, organismal, environmental) where each level can influence each other in a dynamic way. So no single level has a causal priority over another. In biological systems, causation is understood as the process by which one event or state leads to another. So for there to be a privileged level of causation in biological systems, one level would need to be inherently more deterministic or controlling of others, independent of the context that the developing organism is situated. But each level of biological organization (from genes to the ecosystem of the organisms) is interdependent where changes at one level can only be understood in relation to changes at other levels (genetic expression is influenced by cellular conditions, which are then affected by organismal health and environmental factors).

So no level of biological organization operates independently or can dictate outcomes without influence or interaction with other levels. Even what may seem like so-called “genetic causes” require the cell to read the context-dependent information in the gene. So there is a feedback loop where influences are not unidirectional but reciprocal. While genes can influence protein synthesis, the need for proteins can regulate gene expression through feedback mechanisms. Therefore, a priori, there is no privileged level of causation in biological systems, since each level is part of an integrated system where causation is distributed and context-dependent, not localized to any one of the levels of biological organization.

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See these references for more on how genes are necessary, passive causes but not sufficient causes. These references attest to how genes are looked at today in systems biology, not using a reductionist viewpoint. Oyama, 2000; Moore, 2001; Shapiro, 2013; Kampourakis, 2017; Richardson, 2017, 2020, 2021, 2022; Baverstock, 2021; McKenna, Gawne, and Nijhout, 2022. But here is the gist:

“Active causation” is when X causes or initiates an event to occur, whereas “passive causation” is when X is causes to do something or forced to do something by something else or another situation/event. Both Baverstock and Noble argue that genes (DNA sequences) are passive causes, meaning they don’t initiate the causation of traits. Baverstock also argued that the phenotype plays an active role in morphogenesis and evolution, causing changes in processes (which is similar to West-Eberhard’s and Lerner’s views conceptualizing genes as followers, not leaders, in the evolutionary process).

Noble also argues that genes aren’t active, but rather passive causes, since they merely react to the signals from what is occurring in the developmental system and the environment (which, in this case is conceptualized differently in different contexts for the purpose of this argument like the uterine environment, the environments that get created through the interactions of gene products, gene and gene interactions and gene environment interactions which are ultimately caused by the physiological system). He then ultimately, using Shapiro’s “read write genome argument”, argued that the only kind of causation that can be attributed to genes is passive, in the same way that computer programs read and use databases.

Using Oyama’s concept of “information”, it’s not a property of biological things, but is a relational, contextual concept, arguing that is constructed by the history of the developmental system, while information then emerged through the irreducible interactions which are ultimately caused by the self-organizing developmental system; she calls this “constructive interactionism.”

Over the last 40 years since the publication of Oyama’s developmental systems theory and the subsequent strengthening of her view, we’ve come to find out that genes (and genotypes) aren’t causes in and of themselves, and that genes are mere inert molecules, outside of the living cell. So if the cell activates a gene, then the gene transcribes information (remembering how “information” is conceptualized in Oyama’s DST; this premise establishes a causal relationship between the cell and a gene, with the cell activating the gene since the cell is the active cause and the gene is the passive one). If the gene transcribes its information (of which then ontogeny of information is relational and contextual, emerging through the irreducible actions of the developmental resources), then it produces a protein. So if the cell activates a gene, then it produces a protein (the cell being the active cause and the gene and the protein being passive causes).

“But genes load the gun and environment pulls the trigger”

This is a phrase I’ve heard quite a bit, and I think it’s wrong due to what I’ve outlined above. It’s still deterministic and it looks at genes as active causes. The “genes load the gun” part of the phrase assumes that genes have an active role in initiating biological potentials. But we know that genes are acted on by cellular and environmental context, which then dictates genetic expression. It also assumes linear causation, in a one-way, cause-and-effect sequence.

The claim that the environment merely “pulls the trigger” assumes that there is already an inherent “information” that’s in the genes, which is why that’s a genetic determinist claim. It also minimizes the environment to an activator rather than a co-creator of biological outcomes. So using Oyama’s concept of information as something constructed through developmental interactions emphasizes that the environment doesn’t merely activate what’s already there, it also participates in the very construction of biological information and the ontogeny of traits. It also presumes that genes store all relevant information, but we know that it’s dynamically-shaped, using—but not limited to—genes as passive causes. Basically, biological information is an emergent property of biological systems, not a preexisting genetic code.

Furthermore, since we know that the phenotype plays an active role in morphogenesis and evolution, we know that the outcome (the phenotype) isn’t just a result of genetic loading followed by environmental activation. The phenotype actively contributes to shaping genetic expression and evolutionary trajectories. So if genes are activated by the cell and the broader physiological system, then the idea of genes loading anything independently falls apart. Genes are read or used by the physiological system to carry out certain processes in a context-dependent nanner, not setting the stage, but responding to it.

Conclusion

The role of genes in biological systems and causation as discussed by Noble, Richardson, Oyama, Moore, West-Eberhard, Baverstock, Shapiro and others directly refutes the hereditarian/genetic determinist view of what genes do in biological systems. Genes aren’t the primary architects of biological outcomes; instead genes are seen as passive components within a dynamic, interactive system.

By definition, hereditarianism assumes that genes are necessary and sufficient for causes for phenotypes (genes are the primary drivers of trait ontogeny and development). By definition, DST holds that development is an emergent property of a system where genes are just one component among many influencing factors. If development were primarily determined by genetics, then it would contradict the foundational tenet of DST, that development results from interdependent influences. So since hereditarianism and DST are mutually exclusive in their core assertions about the role of genetics in development, hereditarianism cannot be true since we know that a priori there is no privileged level of causation in biological systems.

So quite clearly hereditarianism fails on conceptual, logical, and empirical grounds. The work that’s been done over the past 50 years in biology—both conceptually and empirically—shows that the old way of viewing genes and their role in organismal development just doesn’t work anymore. Biological outcomes are not merely due to genetic blueprints but are dynamically-shaped outcomes, constructed through the irreducible interactions of multiple levels and resources, which then renders hereditarianism simplistic and outdated in the face of modern biological understanding. Noble’s biological relativity argument is a powerful argument that has direct implications for hereditarianism, and the strengthening of the argument from Baverstock and McKenna, Gawne, and Nijhout definitively show the emptiness in any kind of assumptions that genes are active cause of biological processes. Thus, we should ridicule hereditarian views of the gene and what it does in development. It’s simply an untenable view that one cannot logically defend in the face of the conceptual and empirical work on biological systems.

Therefore, to be a hereditarian in 2025 is to show that one does not understand current biological thinking.