Brain size area in women, corresponding to spatial versus language specializations. Small studies have attempted to link brain volume with functional measures such as P300 auditory evoked potentials but finding no association. Studies attempting to related sibling differences in IQ to differences in brain volume are hampered by relatively small sample sizes and the noisy nature of such difference scores, yielding weak evidence for cross-trait cross-sib correlations. The largest brain is that of the sperm whale, weighing about , and killer whales, weighing about . An elephant's brain weighs just over and a bottlenose dolphin's . Brain size tends to vary according
Cryptid whale female individual on Orkney, saying its dorsal fins was similar to a "mizzen mast", and the whale, based on Sibbald’s account, was described as "P. tursio". However, naturalist Georges Cuvier disregarded Sibbald’s claim as a bad description of the carcass, as well as dismissing the name "P. tursio". Another alleged sighting was off the Annapolis Basin, Nova Scotia, Canada on September 27, 1946, where the creature was apparently trapped there for 2 days. Its length was estimated to be between . The Alula whale, or the Alula Killer, or "Orcinus mörzer-bruynsus", was discussed and illustrated for the first time, but