There is a dichotomy in all Humans, Logic vs. Emotion.
A dichotomy is a division into two mutually exclusive, opposed, or contradictory groups. Merriam-Webster.com
Logic represents a collection of experiences and one’s ability to parse their knowledge to find similarity between events, problems, or occurrences in order to cipher the next sensible action required. Logic is at the core of language. All humans develop logic as they learn. Children are taught as they age, mixed with the collection of their experiences, they begin to develop a logical understanding of the world around them which allows for prediction of events or occurrences. Their understanding grows as they encounter each moment. Thus each moment also effects their understanding of each moment to follow. In the instance of two people riding in a car when they begin to slide due to a wet road; for the one who has survived a traumatic event, such as an automobile accident on a wet road, to relive these circumstances will induce fears and worries equivalent to those during and after their accident. Whereas, the other individual who has not experienced such trauma will see or experience little more than a simple worry about the momentary loss of traction.
All humans share the same emotional constructs. While it may take different amounts of stimuli to elicit anger from two different individuals, the manifestation of anger will cause the same response. It will have equal effects on the physiological systems of both of the individuals. Their blood will race; their heart will speed up; their breath will quicken. Emotions are at the center of communication. If communication is the sharing of ideas and thoughts, and emotional manifestations are a similar point of reference, then communication occurs on an emotional level. The innate trait in humans to bond together into groups: couples, families, tribes, clans, etc. stand as proof.
While this has been no more than an introductory peek inside this deeply discussed and often written about topic, let it demonstrate the need that anyone who wishes to be a successful communicator must always work toward mastery of communicating on both of these levels.