Genetic misnomers

Last year it was the 'good mum' gene and now we have the 'perfect husband' gene - the lead story in this week's BioNews. Like it or not, we will have to get used to the idea that genetic variation contributes to variation in behaviour and not just in mice and voles - in all of us. I suspect, like it or not, that we will also have to get used to such headlines.

Most people are fascinated by behavioural research and science journalists have to help sell newspapers. 'Increased affiliative response to vasopressin in mice expressing the V1a receptor from a monogamous vole' - the title of last week's paper in Nature - hardly grabs the attention. Unfortunately, catchy headlines may reinforce common and potentially dangerous misunderstandings about the nature of genetic effects. This is particularly so when they dub a specific bit of DNA as a gene (or even worse the gene) for some complex, socially defined characteristic. It is precisely in such complex human traits as parenting that any genetic influences will be modified by environmental factors. It is not surprising that talk of a monogamy gene leads to rejection of the idea of genetic influences in human behaviour as reductionist nonsense.

Beyond the rare single gene disorders that follow simple Mendelian patterns of inheritance, genetic influences on health, development and behaviour are nearly always complex, multiple and conditional on the environment. It is plain for all to see that there are strong genetic influences on height. Tall parents tend to have tall children. With high doorways a bumped head can hardly be regarded as genetically determined, but lower the doorways and genetic factors start to come into play. Lower them still further so everyone has to stoop and 'the genes for bumped head' tend to disappear again. But, of course, they don't.  People still have the same genes, the same range of genetic variation. Only the doorways have changed.

Naming genes after complex behavioural characteristics is clearly a mug's game and does nothing to enhance the public's understanding of genetics. The challenge is to develop a popular genetic shorthand that reinforces the conditional nature of most genetic effects.

Just a final point on the subject of monogamy. In one 'monogamous' rodent, Peromyscus polionotus, used in genetic studies of monogamy, it turns out that 20% of subsequent litters are by a different father anyway (Foltz, D W. Am. Nat. 117; 665-675, 1981). Perhaps they have human failings after all!