It’s not clear why—medicine? cars? supermarkets?—but the skulls of white Americans, and perhaps of other races and nationalities, have become slightly taller and roomier, according to new forensic research.
New measurements of hundreds of skulls of white Americans born between 1825 and 1985 suggest that their typical noggin height has grown by about a third of an inch (eight millimeters).
It may not sound like much, but the growth translates to roughly a tennis ball’s worth of new brain room.
Beginning with the dawn of the first Homo species, human skulls evolved to be increasingly bigger until about 30,000 years ago, when head size plateaued.
And about 5,000 or 6,000 years ago, when agriculture took off in earnest, skulls began shrinking. The cause of the shrinkage is a mystery…
keep reading – National Geographic – Americans’ Heads Getting Bigger