I would introduce them to scratch regardless of their age. http://scratch.mit.edu/

When you don't have to deal with syntax and can concentrate on nothing but logical components it becomes much easier to understand.

Scratch is a great! I do worry that people would then begin to learn a language and be frustrated by it's syntax. I don't know?

You have to deal with the syntax of a language regardless.

It's a lot easier to deal with that once you've learned how to program. This is why more experienced developers have an easier time picking up a new language.

They already know what purpose an if statement has or how to combine a few conditions and a loop to do xyz. These are things much easier learned in an environment that scratch provides you.

Ruby is a great start because it provides syntax, can be run locally on command line and also has many widely available examples you can read and bootstrap quickly.

JavaScript. Even with its pitfalls and numerous headaches. The first language I learnt was JavaScript and it made it so much easier to learn others afterwards.

Logo, really gives the fundamentals in an accessible way.

I would probably choose JavaScript, Python or Ruby.

Python. If the person is a statistician R

C++ is the best language to understand the basics of programming, its not easy, but its not that hard either. It will make one's foundation strong from the get go.

I agree that C++ gives you a great understanding of programming, but I don't think that people with little or no understanding of programming should have to worry about types, compilers amongst other things. I feel that C++ is a great choice for your second, third or even fourth language.

Lisp