A modern field of study in which the concepts and methods of psychology are applied to religious experience and behaviour. One of the first to investigate such possible applications of psychology was W. James; he studied the experience of well-being or of conflict in human response to God, and the experiences of religious conversion and of saintliness and mysticism. Many of the writings of S. Freud (1856–1939) on psychoanalysis contributed to the psychological study of religion, though his critical and reductionist views of religion no longer command assent. Similarly the conclusions of C. G. Jung (1875–1961), though by contrast tending to assign an almost indiscriminate validity to religious phenomena in human experience, have in turn led to restatements of permanent value for the psychology of religion. Since the early 1960s more sophisticated methods of analysis have been developed. Religious behaviour and experience have been studied in relation to age, to cognitive style and other personal characteristics, and also with reference to pathological and drug-induced conditions. Merely psychological methods, however, cannot fully answer questions about the validity of religious behaviour and experience, even if they can account for some aspects of both in non-religious terms.