His research and ideas have garnered some criticism, particularly from science writer Ed Yong, who points out that oxytocin administration boosts schadenfreude and envy.

[8] Oxytocin administration increases the salience of social cues, suggesting that priming effects in these experiments explain their findings.

[10] Neuroscientist Molly Crockett also disputes Zak's claims, referring to studies that show oxytocin increases gloating, bias at the expense of other groups, and in some cases decreasing cooperation; suggesting oxytocin is as much an "immoral molecule" as 'the moral molecule' Paul Zak claims.

His Ofactor research reflects the approach advocated by his late colleague at Claremont Graduate University, management guru Peter F. Drucker, in which organizations with flat hierarchies empower employees.

[13] Zak's lab has discovered neurologic signals that reflect engagement in stories and predict post-narrative behaviors.

Zak is a member of the Screen Actors Guild and has created and voiced science dialog for movies, including The Amazing Spiderman.

[22] His other TV appearances include Fareed Zakaria's GPS on CNN, the John Stossel show on Fox Business, the Dr. Phil show, TakePart Live on Pivot TV, Fox and Friends, Good Morning America, The Bachelorette, and ABC World News Tonight.