How Do You Think The Four Goals Of Psychology Can Help Or Hurt Humanity?

Just to be clear, before I begin my answer, the four main goals of psychology as I understand them are:

• Description - analyse behaviour and describe its processes, develop a sense of 'normality'
  
• Explanation - explain why behaviour is exhibited
  
• Prediction - predict what kind of behaviour will occur, given certain circumstances
  
• Changing Behaviour - help individuals to get more out of their life
  

How Can Psychology Help Humanity?It seems fairly obvious to point out that gaining an understanding of how we work as individuals, and how we work within groups could only help humanity.Besides being able to help people overcome debilitating psychological problems, psychology also helps us to design a better world. If we can predict human behaviour, given certain circumstances, then we can do this by improving buildings, cars and workplaces, for example.Psychology also gives our lives more meaning, since it moves us away from reliance upon shapeless deities for moral support, and puts the power to understand and improve our lives firmly in our own hands instead.
How Can Psychology Harm Humanity?Psychology is still a young discipline, and we are still a long way off of reaching even a vaguely satisfying understanding of how the human mind works.
As a consequence, the potential for mis-apprehension of a condition, or the mis-understanding of a particular patient's condition always has the potential to do harm.
In the past, certain schools of psychology have held extreme assumptions about behaviour, for example the behaviourist's assertion that all behaviour was determined by external forces.
By overlooking the internal workings of the mind, adherents to this school of thought ran the risk of causing more harm than good if they tried to change the behaviour of a person.
However, I don't believe that this is such a common risk these days due to the more human-centred approach to psychology employed by today's psychologists.