HBS Working Knowledge addresses the question: “Sending e-mail requests for help or information to multiple people will get you an answer more quickly, right? Wrong.” We have all felt this, but Greg Barron articulates the need for personalised email very clearly:
We demonstrated that the more people queried, the lower the proportion of responses. While we were pleased with the clean results, we were not surprised. Social psychologists have been studying the diffusion of responsibility effect ever since Darley and Latan’s (1970) influential studies that were motivated in part by the murder of Kitty Genovese in full view of thirty-eight bystanders who did nothing to help. It seemed natural for us to assume that the effect could be generalized to e-mail requests.
Latan and Darley explained their findings in terms of the bystander’s cue valuethe belief, conveyed by verbal or nonverbal communication, that others are capable of helping. Accordingly, if an e-mail sent through a discussion group is evaluated by its recipient as being sent to many individuals that are capable of responding, the diffusion of responsibility effect would imply a decreased tendency to respond.
The effect of additional addresses in the cc field on the recipient is an interesting empirical question that we have not looked at, but note that in terms of cue value, the cc field is very different from the To field. Almost by definition, recipients in the cc field are not expected to respond to the e-mail so we would not expect a diffusion of responsibility to occur.
Managers need to keep their e-mails personalized whenever possible. It’s that simple. The idea that a personalized communication has a larger impact is supported by a large body of both psychology and marketing literature besides our own line of research.