Why are we waylaid by criticism or unable to get past a minor snub from our best friend? Thats our negativity bias. We humans have a propensity to give more weight in our minds to things that go wrong than to things that go rightso much so that just one negative event can hijack our minds in ways that can be detrimental to our work, relationships, health, and happiness. Overcoming our negativity bias is not easy to do. But a new book, The Power of Bad: How the Negativity Effect Rules Us and How We Can Rule It, coauthored by social psychologist Roy Baumeister and New York Times writer John Tierney, inspires hope.