A recent GWAS looking for gene variants linked to temperament came up empty, says blogger Neurocritic. The study, led by the University of Queensland's Naomi Wray, scored more than 5,000 participants on a temperament scale — determining their harm avoidance, novelty seeking, reward dependence, and persistence characteristics — and looked for genetic variants linked to those scores. In Biological Psychology, the researchers report that "no genetic variants that significantly contribute to personality variation were identified." Neurocritic adds that no previously identified candidate genes, such as the serotonin receptor gene, were even close to showing significance, and the researchers suggest that this is due to missing heritability. Neurocritic, and other bloggers, also point out that the personality test may be flawed. "We're trying to find the genes for personality constructs that don't exist. It's not that people don't have personalities, or that these personalities can't be measured – it's that we aren't the same person in every situation, which is what all these "tests" implicitly assume," writes Jonah Lehrer at Frontal Cortex, adding that that may be the reason the researchers didn't find anything.