Mohawks didn't originate in the 1980's (though I enjoyed the comments on the photo quite a bit). Many Native American tribes (such as, wait for it, the Mohawk) would pluck most of the hair out of their heads and leave a small square with decorated braids or in some cases a strip as seen here. Why this gentleman would have one is a mystery to me, but the inspiration is doubtless from direct or indirect contact with Native Americans sporting the style.