The idea of human function curves shows how we all in our everyday life get things done as a result of a vital force that we call arousal (good stress).
As the diagrams show, three types of curve can be envisaged. They all have certain similar characteristics. With increased arousal (good stress), performance increases roughly in proportion to the degree of arousal until a point is reached where fatigue sets in. Immediately performance falls, and if more arousal occurs exhaustion sets in. This is followed by ill health (stress-related diseases), and finally breakdown.
Not all the human function curves are the same. A man or woman with a high curve can increase performance by increased arousal to a greater level than might otherwise be expected. High curves are enjoyed by those who have been carefully trained and disciplined on a long-term basis. Good mothering, security at work and at home, a well-rooted life in a stable society with a fair modicum of confidence, success and acclaim allow for high performance to be reached without ill health intervening.
But for those who get involved with bad stress on a long-term basis, performance, although heavily whipped by arousal, soon starts to fall off, and exhaustion, ill health and breakdown occur very rapidly. Low curves are predisposed by poor education, low social status, poverty, unemployment, less than good parenting, loneliness and lack of roots both physical and emotional. Low curves can be transiently produced by temporary and environmental factors – for instance extremes of weather, anxiety, overcrowding, lack of success in an endeavour, marriage breakdown, divorce, bereavement and grief. In other words, low curves result when things are going badly for you.
These human function curves are mobile things and not fixed like the A-personality leopard and his spots.
In fact, we probably all function in our day-to-day lives within several variable curves.
The secret of using the function curve to advantage is first of all to heed the fatigue warning – the point when extra effort fails to bring about what we expect of it. By building a regular relaxation routine into everyday living we can encourage our body to function much more efficiently before the point of tiredness and subsequent exhaustion sets in.