Employment involves a great deal of investment of our identity, and often no small means of dependency. As a result of the need to succeed in our careers, we learn to value behaviours that tend to succeed in the business world.
There is, first of all, the general influence of the employment culture. The majority of British managers are ISTJ. Also, each organisation has its own culture or system of cultures. For example, the corporate culture may be extrovert but the R&D division's culture may be introvert. Each job occupation also attracts certain Myers Briggs types and exerts pressure on behaviour. There may be further influences in that managers or supervisors may take on the role of parental figures, and their individual personalities can also have a significant impact on our preferences.
I frequently find, when running MBTI workshops with business teams, that management and staff have previously completed the MBTI as part of a management development programme, but had little confidence in the result. It is only after exploring the difference between true preference and learned behaviour that they come to recognise the tension in their job between the way they want to behave, and the way the culture expects them to behave. Teams often seem to benefit from the greater diversity of having team members resort to their natural preferences.