From what I learned about React, the programmer should describe the state, and the appearance of the component for a given state. React does all the rest. When the state changes, React won’t immediately render anything to the dom. It first runs a virtual dom, and only renders to the dom an element that has been changed (I think I learned it in the React Facebook Tutorial).
According to lesson 37 in the Alpha version
the default behavior is that your component re-renders when it receives new props, even if the props haven’t changed. You can use shouldComponentUpdate() to prevent this by comparing the props.
Perhaps an experienced programmer can clarify things here.
(I’ll also mention the issue in the Github repository)