Node.js vs Ruby (Fibonacci number)

fib.js

var sys = require('sys');
  
function fib(n) {
  if (n < 2) return n;
  return fib(n-2) + fib(n-1);
}

sys.print(fib(39));

fib.rb

def fib n                                                                       
  return n if n < 2 
  fib(n-2) + fib(n-1)
end

print fib(39)