Did Goliath Have Hereditary Gigantism?

Deirdre E. Donnelly and Patrick J. Morrison’s 2014 article “Hereditary Gigantism: The Biblical Giant Goliath and His Brothers”, published in Ulster Medical Journal 83(2), 2014, pp. 86–88, is a medical-genetic hypothesis, not a biblical commentary. Their bottom line is modest: Goliath and several related warriors may plausibly fit hereditary pituitary gigantism, possibly involving AIP, but the case cannot be proved without physical evidence. The paper is useful because it asks whether the biblical pattern of giant warriors could have a coherent medical explanation while still leaving the harder textual and theological questions open.

Could Goliath Have Had Hereditary Pituitary Gigantism? Plausible, Not Proven

Donnelly and Morrison begin with a family pattern, not merely Goliath’s height. In the abstract they write: “The biblical giant Goliath has an identifiable family tree suggestive of autosomal dominant inheritance.” The phrase “autosomal dominant” matters because it describes a trait that can appear repeatedly in one family line when a single inherited variant predisposes carriers to disease, though not every carrier must show the same severity.

Scripture introduces giants much earlier than David’s battle with Goliath. Donnelly and Morrison note in their introduction: “Giants are first described in the Bible in Genesis 6:1–4.” They then move through later Old Testament groups such as Rephaim and Anakim, while acknowledging that the exact relationships among these groups are unclear.

That is an inference from the biblical pattern, not a genetic claim made by the text itself. Genesis 6:1–4 introduces the Nephilim in connection with the “sons of God” and “daughters of men,” but Scripture does not name a medical mechanism, does not use endocrine categories, and does not trace a continuous biological line from Genesis 6 to Goliath. Donnelly and Morrison do not require later giants to be physical survivors of the pre-Flood Nephilim. They briefly allow that later cases of gigantism could have arisen through subsequent genetic mutations.

The paper works mainly from Samuel and Chronicles. It reconstructs Goliath and the later Gathite warriors as a possible family cluster involving Ishbi-Benob, Saph or Sippai, the figure identified as Lahmi in Chronicles, and the unnamed warrior with twenty-four digits. This reconstruction depends partly on harmonizing parallel passages whose wording and relationships are textually difficult, so it should not be treated as a settled genealogy.

Donnelly and Morrison connect that textual cluster to modern endocrine genetics. On a literal reading of their proposed relationships, repeated giant stature could fit an autosomal dominant pituitary-gigantism condition involving a gene such as AIP. The strength of that move is its medical coherence. The weakness is that the family tree is reconstructed from compressed biblical notices, not from a modern clinical pedigree.

They are careful not to turn plausibility into proof. Their conclusion is that Goliath may have had an AIP mutation associated with early-onset autosomal dominant pituitary gigantism, while the six-digit warrior may have had a separate inherited condition involving polydactyly. The key word is “may.” This is a proposed explanation layered over the text, not a recovered diagnosis.

Pituitary gigantism can result when excessive growth-hormone secretion begins before the growth plates have fused, commonly because of a growth-hormone-secreting pituitary tumor. Growth-hormone excess before growth-plate fusion produces gigantism; when it continues or begins after fusion, it produces the characteristic tissue and skeletal changes called acromegaly. Familial isolated pituitary adenoma, or FIPA, can be an autosomal dominant condition with incomplete penetrance, and some cases involve germline mutations in the aryl hydrocarbon receptor interacting protein gene, AIP.

I went to the article expecting more discussion of the Samuel and Chronicles differences behind the family tree. Instead, Donnelly and Morrison largely adopt a literal, harmonizing reading and move quickly to genetics. That does not sink the proposal, but it means the medical side is more developed than the textual side.

How the AIP Proposal Tries to Explain Goliath’s Size and Defeat

The heart of the proposal is that Goliath’s height could have come from a growth-hormone-secreting pituitary tumor, perhaps in an AIP-related familial condition. The abstract puts it plainly: “We suggest that he had a hereditary pituitary disorder, possibly due to the AIP gene, causing early onset and familial acromegaly or gigantism.”

Modern medicine gives that suggestion some weight. AIP-related familial pituitary disease is a real category, and early-onset growth-hormone excess can produce extraordinary height. In principle, several very tall men in one extended family is the kind of pattern that invites an inherited predisposition model.

The authors also use Goliath’s defeat to raise a neuro-ophthalmological possibility. A sufficiently large pituitary tumor could have compressed the optic chiasm and caused a visual-field defect, which they propose as one possible vulnerability during the encounter. The biblical narrative itself reports no visual impairment.

That is medically plausible. Large pituitary tumors can press on the optic chiasm and affect peripheral vision. The proposal becomes more fragile, however, when moved from clinic to battlefield. The biblical text does not state that Goliath had vision loss, does not tell us the precise angle of David’s throw, and does not present the victory as a technical exploitation of an optical defect. The narrative’s stated emphasis is that the Lord delivers Israel through David.

Donnelly and Morrison also avoid over-pathologizing Goliath and his relatives. Pituitary giants may have reduced speed or agility, but the biblical warriors are not presented as comic, lumbering figures. Ishbi-Benob nearly kills David. Goliath terrifies Israel’s army. The better reading is not “large men are medically weak,” but “a serious endocrine disorder could produce great height without eliminating combat effectiveness.”

That distinction matters because a medical explanation can easily become a way of shrinking the story. Donnelly and Morrison do not need Goliath to be helpless. Their claim is narrower: a known disorder could explain unusual stature, possible familial clustering, and perhaps some vulnerability, while leaving the biblical drama intact.

Direct evidence is still absent. There is no skeleton securely identified as Goliath, no imaging of his pituitary region, no hormone profile, and no DNA to test for AIP. The paper notes that securely identified ancient remains could, in theory, be tested someday. Until then, AIP-related hereditary pituitary gigantism remains a coherent scenario, not a confirmed diagnosis.

David’s five smooth stones are another example of useful restraint. Donnelly and Morrison connect David’s selection of five stones with later passages in which David’s relatives fight other giant warriors, while also acknowledging that symbolic interpretations are possible. The AIP hypothesis does not depend on turning the five stones into a genetic-family clue.

The Six-Digit Warrior and the Polydactyly Problem

The most striking member of the later giant cluster is the unnamed warrior in the Samuel and Chronicles material who has six fingers on each hand and six toes on each foot. That is polydactyly, and the biblical description is unusually specific: symmetric extra digits on all four limbs.

Donnelly and Morrison include him because he tests the limits of a single-gene explanation. The abstract says: “We comment on the evidence within the scriptures for his other relatives, including a relative with six digits, and speculate on possible causes of the six digits.” The question is whether one genetic event could explain both the gigantism and the polydactyly.

They consider a large deletion on chromosome 11 involving both AIP and BBS1, a gene associated with Bardet-Biedl syndrome type 1. But they do not settle on that explanation. Bardet-Biedl syndrome can involve rod-cone dystrophy, truncal obesity, cognitive impairment, and postaxial polydactyly. Those additional features are the problem. A deletion broad enough to affect both AIP and BBS1 would likely produce a wider syndrome than the biblical text describes.

The authors consider, but judge unlikely, a contiguous deletion involving AIP and BBS1 because the genes are separated by a gene-rich region and such a deletion would be expected to produce additional features. In genetic terms, the tidy “one deletion explains everything” model carries a cost. It would probably disrupt more than height and digits.

Their preferred explanation is simpler: a separate dominant polydactyly mutation could better explain symmetrical six digits on all four limbs. That is a conservative move. Polydactyly can be inherited as a dominant trait and can occur without the broader Bardet-Biedl pattern. Donnelly and Morrison therefore keep the giant-stature hypothesis and the six-digit detail related at the family level, but genetically distinct.

That restraint is one of the paper’s strengths. Rather than forcing every unusual feature into one dramatic master mutation, the authors let the six-digit warrior complicate the model. They distinguish what AIP-related gigantism could explain from what it probably cannot.

The caution is that the data point is only a brief narrative note. In a modern clinic, geneticists would ask about vision, cognition, obesity, limb patterning, family history, and molecular testing. Here, the discussion rests on a short biblical description. The six digits can be read clinically, but they may also function literarily as a vivid mark of abnormality or threat.

Where the Reconstruction Must Stay Loose

The main limits fall into four areas.

First, the family reconstruction is plausible but not explicit. Samuel and Chronicles link several warriors with Gath, Rapha or Rephaim language, and giant stature, yet they do not hand us a clean modern pedigree. Donnelly and Morrison’s autosomal-dominant model depends on reading those notices as one coherent family line.

Second, the broader giant terminology remains opaque. Nephilim, Rephaim, Anakim, and Philistine giants appear in different biblical settings, and Scripture does not flatten them into one medical category. Donnelly and Morrison are right to avoid insisting that Goliath descends from pre-Flood Nephilim. New mutations could account for later giant families, but that is a genetic possibility, not an exegetical proof.

Third, the battlefield reconstruction is optional. Optic-chiasm compression could fit some imagined versions of David’s sling shot, but the narrative does not require it. The same is true of reduced agility. Medical vulnerability may have been present; the text’s theological point does not depend on it.

Fourth, the work is retrospective diagnosis. No bones, no DNA, no clinical examination, no hormone levels. The paper’s language of “may,” “suggest,” and “possibly” is not scholarly hedging for no reason; it is the correct level of certainty for the evidence available.

For Genesis 6 readers, the boundary is simple: a medical model for Goliath cannot settle the identity of the “sons of God,” the nature of the Nephilim, or the continuity of giant peoples after the Flood. It can only suggest how unusually tall human warriors in David’s era might have arisen under providence through ordinary biological means.

Conclusion

Takeaways: Donnelly and Morrison offer a plausible but unproven explanation for Goliath and the proposed Gathite family cluster: hereditary pituitary gigantism, possibly involving AIP. Their strongest contribution is showing that the biblical pattern can be read coherently alongside modern endocrine genetics. Their best caution is separating the six-digit warrior’s polydactyly from a sweeping AIP-BBS1 deletion theory. The Bible gives us enough to say Goliath was a terrifying Philistine champion defeated by the God of Israel through David; it does not give us enough to diagnose his genome.

Jake Mooney is a lay researcher who has studied Genesis 6 and its history of interpretation for more than twenty-five years. He created Chasing the Giants to bring together Bible-first research on the Nephilim, the Book of Enoch, and related traditions without turning uncertain evidence into sensational claims. He is also writing the forthcoming novel The Descent of the Gods.

I worked directly with Donnelly and Morrison’s 2014 Ulster Medical Journal article, drawing on their own wording where possible, and set it alongside basic biblical exegesis and current endocrine-genetics context to weigh what is plausible, what is conjectural, and what Scripture leaves open.

This subject attracts speculation because it appears to offer hidden explanations behind a familiar biblical story. But Scripture repeatedly warns against allowing signs, secret knowledge, or elaborate theories to displace attention from God’s revealed word. A medical hypothesis can be interesting and even plausible without becoming the real meaning of David and Goliath. The text’s emphasis remains the same: Israel’s deliverance did not depend on human stature, weapons, or natural advantage, but on the Lord.

If you’d like more careful, Bible-first studies on Genesis 6, the Nephilim, and giants after the Flood, you’re welcome to subscribe to the free monthly Chasing the Giants newsletter.