There are many ideas and theories relating to personality - none are, or ever will be complete. People are unique, therefore no theory or framework or test can reveal fully what they are or will be.

For the purpose of this course, it's important to understand that 'personality' does affect communication, since the sender and receiver - two key elements in the communication framework may perceive each other differently and their own self concepts will influence the ‘how’ and ‘what’ of the communication.

'Personality' may be defined as the characteristics and ways of behaving that determine a person's unique adjustment to the environment. The fact that you eat, sleep, communicate and relate to others does not define your personality. It is how you eat, how you sleep, how you communicate, how you relate that determines what you are.

Thus personality is a combination of many factors as shown in the diagram below.

Clearly it is not practical to deal with such complexity in our everyday relationships, hence the relative value of simplified frameworks.
One of the easiest and most readily recognised personality typologies is that developed by Eysenck. He proposed that personalities could be classed as either ‘introverted’ or ‘extraverted’ and ‘stable’ or ‘unstable’. Carl Jung had popularised the first pair of these terms. Their meanings are easily understood.

The extravert is social, outgoing and, when under stress, will seek company. The introvert prefers to work alone and to keep people at a distance (note that introverts will enjoy speaking and teaching provided they can do so at a distance from their lecterns or platforms!) Under stress the introvert will withdraw into self.

The stable person is calm, even tempered and very much in control of his emotions, while the unstable (not a pejorative description) will be restless, excitable, impulsive and moody.

Combining these dimensions gives four major personality types not dissimilar to those identified in ancient times by the Greeks:
Sanguine - warm hearted and pleasant
Phlegmatic - listless and slow
Melancholic - depressed and sad
Choleric - quick and fiery

Further characteristics of the personalities are shown in the figure above.

There are dangers in using concepts such as these - first that we label people and expect them to display all the features of that label. Second, that we lock people into a ‘personality box’ and fail to recognise the dynamic and interactive nature of people. People do change, grow and develop. Third, most people are a combination of the types and although one may dominate, in some circumstances motives can be aroused which transform the phlegmatic into the sanguine or the choleric or vice-versa.

For the purposes of good communication it is useful to recognise the ‘personality type messages’ that are being given and received.