title: staggerChildren with framer motion
body: <p>I'm having some problems getting the framer motions "staggerChildren" transition to work on a simple list of items. It basically allows animations of child components to be staggered.</p>
  
  <p>I got my animation properties set up like this, for the parent container and the children:</p>
  
  <pre><code>const container = {
    hidden: { opacity: 0 },
    show: {
      opacity: 1,
      transition: {
        staggerChildren: 0.5
      }
    }
  };
  
  const listItem = {
    hidden: { opacity: 0 },
    show: { opacity: 1 }
  };
  </code></pre>
  
  <p>Then i fetch an array of items and save it to my users state. And finally just a simple map to render out some data from that array.</p>
  
  <pre><code>export const Example = () =&gt; {
    const [users, setUsers] = useState([]);
  
    useEffect(() =&gt; {
      axios.get("https://reqres.in/api/users").then(res =&gt; {
        setUsers(res.data.data);
      });
    }, []);
  
    return (
      &lt;motion.ul variants={container} initial="hidden" animate="show"&gt;
        {users.map((item, i) =&gt; (
          &lt;motion.li key={i} variants={listItem}&gt;
            {item.first_name}
          &lt;/motion.li&gt;
        ))}
      &lt;/motion.ul&gt;
    );
  };
  </code></pre>
  
  <p>The problem is that those items, while getting rendered does not get staggered and end up getting faded in at the same time. And I'm not exactly sure why. Example of this: <a href="https://codesandbox.io/s/wispy-shape-9bfbr?file=/src/Example.js" rel="noreferrer">https://codesandbox.io/s/wispy-shape-9bfbr?file=/src/Example.js</a></p>
  
  <p>I can get the transition working if i instead use a static array of items stored in variable and then just use the exact same loop. Like this working example: <a href="https://codesandbox.io/s/late-http-vz1s6?file=/src/Example.js" rel="noreferrer">https://codesandbox.io/s/late-http-vz1s6?file=/src/Example.js</a> </p>
  
  <p>But i need this to work with the array i fetch in the useEffect Hook. Anyone knows how? </p>