The thread-opening link here is a blog post by an active researcher on the topic. The blog post links to a recent paper from the Review of Educational Research[1] by a more senior researcher with more details. I have met both of these researchers at professional conferences.<p>[1] <a href="https://s3.amazonaws.com/vu-my/wp-content/uploads/sites/826/2013/02/03094405/Article-RER-Lubinski-2016-F-1.pdf" rel="nofollow">https://s3.amazonaws.com/vu-my/wp-content/uploads/sites/826/...</a>