of those with criminal convictions, but found no evidence that XXY or XYY men were inclined to be aggressive or violent. 1980s and later The March of Dimes sponsored five international conferences in June 1974, November 1977, May 1981, June 1984, and June 1989 and published articles from the conferences in book form in 1979, 1982, 1986, and 1991 from seven longitudinal prospective cohort studies on the development of over 300 children and young adults with sex chromosome abnormalities identified in the screening of almost 200,000 consecutive births in hospitals in Denver, Edinburgh, New Haven, Toronto, Aarhus, Winnipeg, and Boston from 1964 to 1975. These seven studies—the only unbiased studies of unselected individuals with sex chromosome abnormalities—have replaced the older, biased studies of institutionalized individuals in understanding the development of individuals with sex chromosome abnormalities. In May 1997, Nature Genetics published the discovery by Ercole Rao and colleagues of the X/Y chromosome pseudoautosomal region (PAR1) SHOX gene, haploinsufficiency of which leads to short stature in Turner syndrome (45,X). It was subsequently postulated that the increased gene dosage of three SHOX genes leads to tall stature in the sex chromosome trisomies 47,XXX, 47,XXY, and 47,XYY. In July 1999, Psychological Medicine published a case-control study by Royal Edinburgh Hospital psychiatrist Michael Götz and colleagues that found an increased rate of criminal convictions among seventeen XYY men identified in the Edinburgh newborn screening study compared to an above-average-IQ control group of sixty XY men, which multiple logistic regression analysis indicated was mediated mainly through lowered intelligence. In June 2002, the American Journal of Medical Genetics published results from a longitudinal prospective cohort Denver Family Development Study led by pediatrician and geneticist Arthur Robinson, which found that in fourteen prenatally diagnosed 47,XYY boys (from high socioeconomic status families), IQ scores available for six boys ranged from 100 to 147 with a mean of 120. For the eleven of fourteen boys with siblings, in nine instances their siblings were stronger academically, but in one case the subject was performing equal to, and in another case superior to, his siblings. Society and culture Some medical geneticists question whether the term "syndrome" is appropriate for this condition because many people with this karyotype appear normal. In popular culture In June 1970, The XYY Man was published—the first of seven Kenneth Royce spy novels whose fictional tall, intelligent, nonviolent XYY hero was a reformed expert cat burglar recruited