As is well known to regular readers of my posts I often enjoy reflecting on the real scientific and medical parallels of phenomena in George RR Martin’s A Song of Ice and Fire series. Most recently a thought came to me regarding Maegor the Cruel, the third Targaryen King. While much discussion has been dedicated to his reign and how deserving he is of his epitaph in this post I wish merely to reflect upon certain biological and physical aspects which defined the king and explore the possibility that he was an XYY male.
Central to this exercise is a brief reflection on the real and perceived phenotype engendered by the XXY genotype. Firstly, those with the XYY chromosomal complement demonstrate rapid growth from early life and ultimately achieve average final heights approximately 7 cm (3″) above expected final height. Additionally, in a number of studies the IQ scores of 47, XYY boys were usually slightly lower than those of their siblings with approximately 50% of 47, XYY boys identified by newborn screening programs presenting with learning difficulties. Behavioral problems have also been noted in some cases and while debunked now increased aggression and overrepresentation in the prison population was frequently ascribed to XXY males in the past.
With the brief preview above in mind, we can now turn to Maegor. Considering his build, the kind was noted for being a substantially larger newborn compared to his elder brother and being able to outcompete older teens and adults in combat sports by the age of 12-13. He was also noted for having a larger build than his father Aegon the Conqueror himself described as “tall, broad-shouldered and powerful in appearance.” During this same early stage of his life, Maegor was noted for a number of behavioral outbursts including stabbing to death a horse that had kicked him and attacking the stable boy who came to its aid. The title by which history in his own world remembers him and records of his reign speak to this being a continued pattern throughout his life. While towering over his brother physically, intellectually his brother and predecessor Aenys was noted as a renowned poet and singer while Maegor has not such culture pursuits noted. While having begun the research all these findings align with George RR Martin hinting at XXY as an explanation for Maegor what motivated my exploration was a finding I now realize is inconsistent with this genotype; Maegor’s fertility challenges. King Maegor notoriously married multiple times due to his failure to produce an heir. By the time of his death, he succeeded only in fathering three stillborn children notably for congenital defects by his six queens.
Based on even a cursory assessment of Maegor the Cruel we see a representation of how a lay author would present an XYY individual. It is hardly surprising that a non-scientist would assume that a chromosomal abnormality would result in fertility issues given that in many other conditions such as Klinefelter they certainly do. The aggression and behavioral challenges that he ascribes to Maegor also speak to the popular cultural understanding and representation of XXY males as do the physical descriptors. The final piece of evidence is more meta. Looking over Martin’s entire corpus he exhibits an enormous fascination with genetics and heredity in works such as Tuff Voyaging, Night Flyers, and other parts of a Song of Ice and Fire without fully reflecting scientific reality.