Tattooing is on the rise, but new research says people are regretting them more and more. Today we explain the science behind how tattoos work, the history of tattooing on humans (and why we've done it for thousands of years) and how tattoo regret might be on the rise.What Did We Learn This Week:Cigarette companies are creating popular foods that are bad for usPopulation studies are now using cell phones to understand how many people are alive on EarthSTUDYTIME: Tattoos - are they going out of style? Hosted on Acast. See acast.com/privacy for more information.