The book Sons and Lovers by D H Lawrence can be considered a psychological novel in terms of its close description of the relationships within it and their effect on the personalities portrayed. The main relationships to examine are between mother and son (Paul and Mrs. Morel) boyfriend and girlfriend (Miriam, Clara and Paul) and also between Mr and Mrs. Morel. It has long been posited by psychologists and psychiatrists that the most fundamental and profound relationship in a man's life is that between himself and his mother (Freud not least among them.) Positive, happy liberating relationships are considered healthy outcomes for early manhood - repressive, smothering and dominant ones are considered less so. Where it ties in with the girlfriends is the area of emotional attachment. Look to see how Paul's adult relationships may have been affected by the mother/son dynamic.