Many years ago, I wrote a blog -- no longer online, I'm afraid -- about how I associated different programming languages with different shapes. I've never heard of this effect before today, but it visualises almost perfectly what I was trying to express all those years ago. (I originally posited that it was some form of synaesthesia.)

For example, Python has a rounded or smoother shape, whereas C-style languages are more kiki-like (with JavaScript being the spikiest); Haskell, IIRC, had a squarish lump kind of appearance. I originally wrote myself off, thinking that maybe the shapes very loosely correspond to how the code looks in each language "from a distance", but I was never really satisfied with that.