How many thumbs do humans have?

Depends on the country. A serial hitchiker from Saudi Arabia may have non while a pampered middle class boy from the West Country (such as myself) might have an almost overabundant two…. read more

His recent paper in the Journal of Human Evolution suggests that an overlooked factor in thumb evolution is the nondominant hand—the one that holds the rock while the dominant hand shapes it into a stone tool. A rock for throwing is a kind of tool, of course, and the cupping grip a way of using it. read more

There are about 7 billion humans. If each has two thumbs, more or less, then humans have about 14 billion thumbs. read more

If neither of your parents have or had six fingers though, it is possible for it to also be a genetic mutation that occurred while you were growing in the womb. Either way though, it's a regular occurrence in humans, not abnormal. read more