Sugar and spice

Even as little as two decades ago, science writers could not assume that the word ‘gene’ was widely understood. It had to be defined and discussed. Today, stories about genes for various traits come so thick and fast that journalists no longer need to pause and explain what genes are.Awareness of material inheritance is now widespread. The only problem is that everyday parlance has simplified a complex situation. A scientist reminding us of polygenetic characteristics, predispositions, and nature versus nurture easily sounds like a tiresome prevaricator, unable or unwilling to clarify something that is really very simple. Everyone knows (wrongly) that there are genes for aggression, obesity and homosexuality.It is against this background that one recent media furore should be assessed. The occasion was the publication of a paper by Skuse and his colleagues [1xEvidence from Turner’s syndrome of an imprinted X-linked locus affecting cognitive function. Skuse, DH, James, RS, Bishop, DVM, Coppin, B, Dalton, P, and Aamodt-Leeper, G. Nature. 1997; 387: 705–708Crossref | PubMed | Scopus (292)See all References[1] which dealt with ‘social cognition’ — those aspects of cognition that facilitate smooth social relationships. The authors said that their observations “suggest that there is a genetic locus for social cognition, which is imprinted and is not expressed from the maternally derived X chromosome.”In an accompanying commentary McGuffin and Scourfield [2xA father’s imprint on his daughter’s thinking. McGuffin, P and Scourfield, J. Nature. 1997; 387: 652–653Crossref | PubMed | Scopus (16)See all References[2] provided helpful background and then highlighted one implication of the work. “Throughout most of the second half of this century, with the increasing emphasis on sexual equality, there has been a tendency to play down the possible role of biology in accounting for psychological differences between men and women,” they wrote. “Now, for the first time, we have evidence about the location of a gene that plays a part in behavioural sexual dimorphism, challenging the prevailing belief that gender differences are largely culturally determined.”Presented with a topic of abiding human interest, combined with the high frontier of human genetics, the media had a field day. Tabloid and broadsheet newspapers, television current affairs programmes and radio talk-ins publicized the new gene and how it accounted for the differing social skills of men and women. On 12 June the front page of The Guardian announced that “Genes say boys will be boys and girls will be sensitive”. As compared with many other headlines, this was comparatively restrained.Overall, the impression created by press coverage of the paper was that investigators had pinpointed a gene giving females, but not males, specific social abilities. As pointed out on 14 June by two other contributors to The Guardian, Susie Orbach and Joseph Schwartz, “you might have been forgiven for thinking that this was the work of molecular geneticists or was derived from the human genome project. You might have thought that the research had a physical, material basis to it.”In fact, Skuse et al. had not done any gene mapping at all. They had used questionnaires in which parents scored various aspects of their offsprings’ interactions with other people. Questions included the childrens’ sensitivity to the feelings of others, their ability to interpret body language, their responses to commands and their awareness of acceptable social behaviour.Moreover, the study was based not on normal subjects but on patients with Turner’s syndrome, a condition in which part at least of one X chromosome is absent. People affected are short in stature and female in appearance but show poorly developed secondary sexual characteristics. Their intelligence is usually normal, but they tend to have problems of social adjustment.Skuse and colleagues chose these subjects to test their hypothesis that genomic imprinting may occur at a gene that influences social cognition. They compared 55 Turner’s syndrome women whose single X chromosome came from their mother with 25 who had received it from their father. Their conclusion, quoted above, was based on the finding that the latter group had better social skills.Why, then, did this reasonably guarded conclusion lead to such unwarranted excitement? Three things probably triggered off the clamour. Firstly, the authors underlined the significance of their work by giving a press conference. Secondly, Nature published a commentary going beyond the authors’ ‘suggestion’ to talk of “evidence about the location of a gene…”, and issued a media release promoting the paper.Then journalists got busy. They, with their editors and headline writers, ‘strengthened’ the story further. Many accounts had no room for caveats, such as the imperfect definition of social cognition, the inherently subjective nature of the evidence or the validity of generalizing from a small group of highly atypical individuals to the entire population of boys and girls, men and women. Some accounts did not even mention Turner’s syndrome.In muddy and hazardous waters of this sort, would it not be prudent for all involved in such chains of communication to be more cautious?