The question "Who is the biggest head in the world?" is a somewhat subjective one, as there is no universally agreed-upon definition of what constitutes a "big head." However, there are a few individuals who are known for having particularly large head sizes due to medical conditions or other factors.
One example is Sandy Allen, who was listed in the Guinness World Records as the tallest living woman from 1976 until her death in 2008. She suffered from a rare form of gigantism known as pituitary gigantism, which caused her to grow to a height of 7 feet 7 inches and also resulted in a proportionately large head size.
Another individual known for having a large head is Rezvan Bahrami, a woman from Iran who has been diagnosed with hydrocephalus, a condition in which cerebrospinal fluid accumulates within the brain and causes it to enlarge. Bahrami's head measures over 33 inches in circumference, which is significantly larger than the average head size of around 22 inches.
In some cultures, head size has been seen as a symbol of intelligence and wisdom, leading to practices such as artificial cranial deformation in which infants' heads are intentionally molded into a desired shape. While these practices have been largely discredited and abandoned, they demonstrate the historical significance placed on head size in some societies.
In conclusion, determining the "biggest head in the world" is a subjective matter that can vary depending on cultural beliefs and definitions. However, individuals such as Sandy Allen and Rezvan Bahrami are known for having particularly large head sizes due to medical conditions.