How INTPs can develop
The development of personality occurs in phases throughout life. For someone who is young, the main task is to develop use of their preferred mental functions. As one matures, however, and approaches midlife, there is often a need to develop greater comfort with using your non-preferences. This can help you increase your performance at work, and increase your ability to deal with different people and circumstances.
As with all types, an INTP can achieve personal growth by developing all functions that are not fully developed, through actions such as expressing appreciation towards others, working within other people's limitations, and accepting and praising others' imperfect efforts. You may need to learn to put up with 'good enough' efforts, consult others more, and involving them in decisions to engender collective ownership of the solution. You may also benefit from spending time to develop personal relationships for their own sake, and also from learning to acknowledge and develop your own emotions and personal values.
A common theme of development for all types after midlife is individuation. This involves learning to value and develop various "opposites", not just the opposite typological preferences. Through reconciling opposites, your personality becomes more individual and unique, and your personality type may change. You might also reach the stage where your closest personality type is no longer a description of you, but it is merely a part of your personal history.
Next: INTP and Stress