Problematic Textbook Pictures

Over at HappyPlace.com, there’s a great collection of problematic images from student textbooks. Consider this image from a math textbook:

My guess is that the photo below is either from a social studies textbook or the pamphlet for a fraternity:

Here’s a snippet from science textbook whose purpose is to scare the crap out of people who don’t have red-green colour vision confusion (it used to be called “colour blindness”):

Sorry, if you have red-green colour vision confusion, you’re not going to see the humour in this one…