جمجمه‌های عصر آهن نشان می‌دهد که برخی از نوزادان مدت‌ها قبل از کمپین «بازگشت به خواب» به سندرم سر صاف مبتلا بوده‌اند.

Iron Age skulls reveal some babies had flat head syndrome—long before the 'Back to Sleep' campaign

Nearly 3,000 years ago, in central Italy, dozens of Picene people were laid to rest curled up on their sides, as if asleep. When their eternal slumber was disturbed thousands of years later, researchers noted a curiously familiar pattern, one many modern parents and doctors fret over: As infants, many of them had developed a flat spot on their heads.