All ages admitted. There is no content that would be objectionable to most parents. This is one of only two ratings dating back to 1968 that still exists today.
Right from the start when the opening piece to camera sees "Hellstrom" almost walk into a tree, there's something a little dodgy about the presentation. No, he's not a real scientist. He's an actor called Lawrence Pressmann and he's not delivering his own painfully garnered research, but an hybrid of that of others. That gimmick doesn't really matter, though, as once this docu-drama gets under way...