Out? , . , amount to. how did they work that out? , ,., ., ., out? this was comparisons of data that have been _ out? this was comparisons of data that have been published - out? this was comparisons of data that have been published in i out? this was comparisons of data that have been published in the i that have been published in the past, so as we age, on average, our brains shrink a little bit past, so as we age, on average, our brains shrink a little hit every year, so they did is they took the 15 cm that you mentioned and looked at how long it takes for your normal ageing brain to lose 1...