This article writes about the variation in speech rate. Some languages tend to have more syllables per a second. For example, French, Japanese, and Spanish speakers tend to have speak more syllables per a second (almost 8/s) than German, Vietnamese, or Mandarin speakers (roughly 5/s). Although stereotypes exist relating to speech rate, there is no connection between intelligence and speech rate. One significant and consistent variable in speech rate is age. Children speak slowly, then speed up until their 40s, then slow down again in their 50s and 60s.
