No, that's only true _if_ a child component is explicitly attempting to optimize its performance by doing shallow equality checks on its props in `shouldCompone

No, that's only true _if_ a child component is explicitly attempting to optimize its performance by doing shallow equality checks on its props in `shouldComponentUpdate` (or is a `PureComponent`, which does the same thing automatically). Otherwise, React's default behavior is to re-render a component tree all the way down anyway, so it doesn't matter whether a given prop has actually changed its reference or not. See this post by Ryan Florence that explains why "arrow functions in render" is not a big deal: https://cdb.reacttraining.com/react-inline-functions-and-performance-bdff784f5578 https://cdb.reacttraining.com/react-inline-functions-and-per...