59 Certainly one of the principal characteristics which seem to be typical of our age is an increase in social relationships, in those mutual ties, that is, which grow daily more numerous and which have led to the introduction of many and varied forms of associations in the lives and activities of citizens, and to their acceptance within our legal framework. Scientific and technical progress, greater productive efficiency and a higher standard of living are among the many present-day factors which would seem to have contributed to this trend.
Source: Mater et Magistra (Vatican.va)