The complexity of signals in the brain seems to decrease as the nervous system develops in fetuses and babies – and does so significantly faster in males compared with females.
Joel Frohlich at the University of Tübingen in Germany and his colleagues used an imaging technique called magnetoencephalography (MEG) to measure the magnetic fields produced by the brain’s electrical currents in 43 third-trimester fetuses and 20 babies, aged between 13 and 59 days old, to sound stimuli. Of the babies, 16 had also been recorded…