Is Walter Mitty a psychopath?

The term "psychopath" seems very strong to apply to a meek, inoffensive man like Walter Mitty. For example, many psychopaths are considered dangerous because they lack feelings of empathy for other people. In several of Walter Mitty's daydreams, or fantasies, he shows consideration for others. In his second fantasy he imagines himself in the role of a famous doctor who is called in to assist other doctors who are inadequate to handle a delicate operation,...

The term "psychopath" seems very strong to apply to a meek, inoffensive man like Walter Mitty. For example, many psychopaths are considered dangerous because they lack feelings of empathy for other people. In several of Walter Mitty's daydreams, or fantasies, he shows consideration for others. In his second fantasy he imagines himself in the role of a famous doctor who is called in to assist other doctors who are inadequate to handle a delicate operation, and he saves the life of the patient. In another fantasy he is a substitute for another aviator who is suffering from nervous exhaustion. In the courtroom scene Mitty appears to be accepting responsibility for a murder actually committed by a beautiful woman he loves.

“I could have killed Gregory Fitzhurst at three hundred feet with my left hand.” Pandemonium broke loose in the courtroom. A woman’s scream rose above the bedlam and suddenly a lovely, dark-haired girl was in Walter Mitty’s arms. The District Attorney struck at her savagely. Without rising from his chair, Mitty let the man have it on the point of the chin. “You miserable cur!”

According to an article titled "What Is Psychopathy?" in Psychology Today, accessible on Google:

The psychopath can appear normal, even charming. Underneath, he lacks conscience and empathy, making him manipulative, volatile and often (but by no means always) criminal.

None of these descriptive terms seems to apply to Mitty. He does not seem in the least manipulative, volatile or criminal. Psychopaths supposedly show a lack of "social emotions" such as shame, guilt and embarrassment. Walter Mitty seems to suffer shame and embarrassment in various places throughout the story, such as when he is unable to park his car properly and when a woman laughs at him for saying "Puppy biscuit" to himself.

Mitty even feels guilty and embarrassed about his fantasy life. That it why it is called his "secret life." Rather than being a psychopath, Walter Mitty seems to be an extreme introvert who is more interested in his inner world than in the world around him. No doubt this was true of James Thurber himself.