Our brain weighs between 1.2 and 1.5 kilos, but elephant brains weigh between four and five kilos, and whale brains can weigh up to nine kilos, which is why scientists used to resort to saying that our brain must be special to explain our cognitive abilities.
El nostre cervell pesa entre 1.2 i 1.5 quilos, però el cervell d'un elefant pesa  entre 4 i 5 quilos, i el cervell d'una balena pot arribar a pesar 9 quilos, aquesta és la raó per la que  els científics acabaven dient que el nostre cervell havia de ser especial per explicar les nostres  habilitats cognitives.