Altruism in the wild: when affiliative motives to help positive people overtake empathic motives to help the distressed
Journal of Experimental Psychology General (2014) - Comment
pubmed: 24364686  doi: 10.1037/a0035464  issn: 1939-2222  issn: 0096-3445 

David J. Hauser, Stephanie D. Preston, R. Brent Stansfield