The relative age effect in selection of ab initio pilots-Revisiting Gladwell's famous claims

A relative age effect (RAE) has been found in education and sports, with students born earlier in the school year attaining higher levels of success. This was brought into public consciousness through Malcom Gladwell's Outliers: The Story of Success. However, the effect has not been thoroughly examined in other contexts. Thus, with regards to the context dependency of the RAE, and the specificity of which abilities it affects, there are unknowns. The aim of the present study was to scrutinize the tests in use in commercial aviation and explore whether there is a bias based on birthdate in competitive selection procedures assessing operational and cognitive abilities, outside of traditional education. Potential suboptimal selection has implications for flight safety. Associations were studied between relative age and test scores (of cognitive ability, manual spatial ability, and multitasking ability), as well as acceptance for higher education in commercial aviation in Sweden, in 1113 ab initio candidates. Relative age neither had a significant correlation with any of the six performance scores, nor with an aggregated factor score (r = -0.009, p = 0.791), nor predicted flight-school admission (b = 0.036, p = 0.210). Chronological age was associated with manual spatial ability, yet neither correlated with aggregate score nor with admission. The results may be an indication of the RAE having faded in early adulthood, and/or that indirect exposure of education does not benefit candidates in operational tests in early adulthood. Thus, neither relative age nor chronological age seemed to bias the results. For the effects of RAE to persist- or occur in operational abilities- competition between candidates in selection and subsequent relevant exposure (e.g., training/schooling), may be needed. Overall cognitive ability is likely more predictive of success when variance in specific enhancing exposure is limited.