A good deal of the best-known work on the relationships between the sexes among humans has concentrated mainly on two aspects of this subject: either the physical or the psychological implications of sexual interaction have been quite widely discussed in literature easily available and often popularly presented. Without wishing to minimize the importance in its time of the work of Alfred Kinsey and his colleagues, one cannot help feeling, as Richards (1969) has recently observed in this journal, that since all primates copulate in much the same way, one is not going to achieve great insights by examining this in much detail. It is the humanity, not the animality, of man which provides the most significant part of his behaviour in this field. No one can write on this theme without paying due tribute to the work of Margaret Mead (1950), but much of it has concentrated on looking at ways in which upbringing in different societies makes people feel differently about their male and female roles.