Unfortunately, I can&#x27;t access the publication at the moment. You can read the abstract here: <a href="http:&#x2F;&#x2F;www.nber.org&#x2F;papers&#x2F;w21610" rel="nofollow">http:&#x2F;&#x2F;www.nber.org&#x2F;papers&#x2F;w21610</a><p>Whatever measurement they made that they&#x27;re calling &quot;hyperactivity,&quot; it seems to have a strong inverse association with academic achievement, so perhaps it warrants concern regardless of how well it relates to our concept of &quot;self-regulation.&quot;