When it comes to making an interpersonal relationship, you may be inclined to think a voicemail is more effective than an email since the recipient gets to hear your voice. According to a new study from researchers at Indiana University, the exact opposite is true.

Published in the journal Computers in Human Behavior, the study has found that romantic feelings are better expressed in an email than a voicemail message. As counterintuitive as it may seem, an email is the best way to connect with millennials.

“The bottom line is that email is much better when you want to convey some information that you want someone to think about,” said Alar R. Dennis, one of the authors of the study and the John T. Chambers Chair of Internet Systems in IU’s Kelley School of Business.

If you are perplexed about what makes emails more effective, then know that there is one underlying reason: the content. Emails contain more thoughtful language (perhaps because the sender gets time to craft and compose their words), which leaves the recipient more emotionally aroused.

“When writing romantic emails, senders consciously or subconsciously added more positive content to their messages, perhaps to compensate for the medium’s inability to convey vocal tone,” wrote Dennis and co-author Taylor M. Wells, an assistant professor at California State University – Sacramento, in their paper. “Email enables senders to modify the content as messages are composed to ensure they are crafted to the needs of the situation. Voicemail lacks this feature. A sender records a voicemail in a single take, and it can be sent or discarded and re-recorded, but not edited. Thus senders engage with email messages longer and may think about the task more deeply than when leaving voicemails. This extra processing may increase arousal.”

The findings from this study contradict previous research and age-old dating advice derived from common sense. The one takeaway is that more research needs to be done, especially as the population relies more and more on digital communication.

"There's a lot of theory that says email and other text communications don't really work very well," said Dennis. "We should probably go back and reconsider a lot of the stereotypical assumptions that we hold about email and text messaging that may not hold true when we take a deeper look at how people react physiologically."