The most acute problems of new urban families occur in developing countries or among people who have migrated from developing countries to industrial centres in developed countries. Adjustment problems may also occur with families taking part in a rural exodus in developed countries. Major problems occur with nutrition and housing, industrial or service employment and the more constant use of money. With the greater fragmentation of society, the loss of the extended family, commercial pressure and overcrowding, psychological adjustment to city life may be very difficult or impossible to achieve, leading to family breakdown, crime, or anti-social behaviour.