The American organisational psychologist, Edwin A. Locke pioneered the goal-setting theory. The simplest and most direct explanation of why some people perform better than others is because they have different performance goals. I think that nothing intelligent has ever come from intelligence alone, and nothing reasonable has ever come from reason alone. The essence of the theory is:

• Difficult specific goals lead to significantly higher performance than easy goals, no goals, or even the setting of an abstract goal such as urging people to do their best.

• Holding ability constant, and given that there is goal commitment, the higher the goal the higher the performance.

• Variables such as praise, feedback, or the participation of people in decision-making about the goal only influence behaviour to the extent that they lead to the setting of and subsequent commitment to a specific difficult goal.