Whether you're left- or right-handed may not be heavily influenced by genetics compared with other factors, a new study suggests.


Researchers looked at the genomes of 3,940 twins who were part of the London Twin Research Unit, but were unable to find any part on the genome that was associated with handedness "at a genome-wide level of significance," they wrote in the Heredity study[1] .


"There should be a detectable shift between right and left handed people because modern methods for typing genetic variation cover nearly all of the genome. A survey that compared the whole-genome genotypes for right and left handed people should leave such a gene nowhere to hide[2] ," study researcher John Armour, a professor of human genetics at the University of Nottingham, said in a statement.


But that's not to say that genetics don't play any role in handedness. It's "likely that there are many relatively weak genetic factors in handedness[3] , rather than any strong factors, and much bigger studies than our own will be needed to identify such genes unambiguously," Armour added. But "even if these genes are identified in the future, it is very unlikely that handedness could be usefully predicted by analysis of human DNA."


Past research has hinted that genetics may play some sort of role in handedness. A study published earlier this year in the journal PLOS Genetics identified a network of genes involved in the establishment of "left" and "right" in embryos, which the researchers of that study said could have an impact on handedness[4] .