Some meta analyses and studies have questioned the size and existence of the ego depletion effect.[1] The ultimate validity of those later studies is not universally agreed.[2] Martin Hagger and Nikos Chatzisrantis, whose 2010 meta-analysis seemed to support the existence of the ego depletion effect,[5] subsequently performed a pre-registered 23 lab replication study which found no ego-depletion effect.[6]