Marxism and psychology

Marx and Engels described Capital as a relationship and capitalism as a system of relationships. Did they mean that every aspect of our relations with ourselves, others, and society is shaped by capitalism, so that a socialist revolution would transform all of these relationships? Or were they being too general? Are some aspects of human experience unaffected by society, so that we need something other than marxism to understand them and something more than socialism to transform them? This is the core of the conflict between marxism and psychology.