Sometimes we justify our preference for a particular programming language by it's naturalness or intuitiveness. I'm always bothered by this - when other people do it ;-)|
So I was delighted to see that there are papers on Programming Language Design in the Psychology of Programming Interest Group (PPIG) Workshops. I'll resist the temptation to create a new topic for everything that was of interest to me, and just list a few topics here:
Evaluating a new programming language So Microsoft did do usability testing of C#!
The Science of Web-Programming Functional Programming in PHP
How do people check polymorphic types?
Gotos Considered Harmful and Other Programmersí Taboos