Want to be a more impactful communicator?
 
Speak more slowly.

Analyzing hundreds of customer service calls (+ experiments) finds that:
-Speaking more slowly (within a range of normal speaking speed) boosts customer satisfaction and positive evaluations
-Works because it makes communicators seem more empathetic (i.e., signals that they care and understand about their audience's needs)

These are the results of a recent research conducted by our Giovanni Luca Cascio Rizzo (Senior research fellow @ Luiss-X.ITE) and Jonah Berger (Associate Professor of Marketing @ Wharton) cited by Harvard Business Review (Vol 103 (3-4), p. 22).