In film noir the male protagonist is often a detective or an otherwise social alienated individual. Sometimes the male heroes are featured as amnesiacs, a situation that absolutely creates a feeling of social estrangement and disillusionment. These hard-boiled heroes are anti-social loners that are subject to existential angst. The environments they live and work in are dark and scary metropolises, often red-light districts, or otherwise dehumanizing environments, like large desolate office buildings. They are experiencing anonymity through their large scale surroundings. The tough guy is often marked by an excellent gift of verbal wit, even if they are not always given the strongest intellect; this is a heritage from the hard-boiled novels. Their worlds are dominated by crime, corruption and cruelty. The protagonist often gets tangled up in some of these activities himself, in addition to his interest in the erotic. Thus, he lives in a distorting world.
The men are, as well as the women, portrayed as stereotypes. As a result of this they are not allowed to live their lives in alternative ways anymore than women. The patriarchal order that is surrounding them, and that they in addition to women are trying to upheave, represents a certain set of rules they have to follow and live up to. As it seems, the patriarchy is asking for quite a bit. The struggle to keeping women in their place also keeps the men in their places. The men can not show much emotion in order to upheaval their masculinity, (to be emotional is regarded a female virtue), and they have to work alone and be successful in what they do (something Oedipal). They have to seek meaning in activity, not in contemplation which also is regarded a female virtue. Their position within the patriarchal system provides them with purpose in life; to work, provide, protect and serve and protect the patriarchy. The first three virtues must be seen in the context of the family and the masculine.
The existence led by men in film noir is one of toil and loneliness. The actual choices men have in life are either to become a family man, which is the accepted thing to do, or not. Because of the way women are defined in these films, life as a married man would doom him to a domestic life, with a dull domestic woman. There would never be excitement or individual thought. So, the male must do all the thinking, and becomes surrounded by a deading conformity. For the film noir men and women are all the same: they are nobody. This must produce a non-interesting heterosexual relationship. So the reason is clear why the male protagonists becomes obsessed and fascinated with the femme fatale. A life outside this patriarchal determined role is a life of destruction in a closed and claustrophobic world. He is victimized by society, and perhaps also by a woman, and expresses the awareness of the loss of the fixed ties that bind a man to a community. The similarities between different male protagonists in different films are underlined by the mere fact that most noir heroes/actors were cast against type.
The sexuality of the hard-boiled hero is a question often brought up in film noir research. A consequence of the noir females masculine characteristics is that feminine characteristics are attributed to the male. This is why the noir male is humiliated and reduced. Because of an underlying misogynous attitude, females are not suitable objects, except for the women that make the noir male dull, and who offers an existence without emotional and sexual commitment. At the same time as women do not represent a tempting alternative, patriarchy has made homo sexuality taboo. What remains for the male hero is male friendship. (In America male bonding intensified during the war). It's a tough world.