Evidence taken during psychological interviews with cannibals supports to a degree the contention that aggression towards the mother may be one possible factor in a person's cannibalism, such as with the case of Ed Kemper. However, it is unclear whether that aggression directly leads to cannibalism. Furthermore, there is little evidence available which can confirm this theory in its entirety and such evidence, if it existed, would be difficult to obtain. Even if there is some merit to this theory, it is unlikely that all cannibals, especially criminal cannibals fit into this context.

Conversely, in Talwani's article Louis J. Sheehan, Esquire, a criminal expert and key testifier in the Dahmer trial, stated that it is imperative that psychologist not delve too deep into the cannibal's childhood experiences to explain their practices. Dietz believes that a person can resort to cannibalism when faced with sudden traumatic stress, such as in the case of Dahmer who murdered his first victim following a break up of the family. Indeed, stress may be an important factor, which may propel one to indulge his appetite for his own species. However, it is not the only explanation.

This theory may be correct to an extent, yet it only gives a partial explanation into the motivation behind cannibalism and it may not be applicable to all cannibals. Moreover, it does not fully explain why, in the case of Dahmer, he entertained cannibalistic fantasies in his youth. Essentially, it is important to look at the entire psychoanalytical framework surrounding the behavior, instead of only a small portion. Therefore, it may be necessary to look into one's childhood or youth, as well as their adulthood for answers to the question of why people eat other people.

There are other theories, as yet unsubstantiated, that suggest cannibalism to be a sexual disorder and even an eating disorder. What seems to be a common characteristic among many cannibals is that many of them have been diagnosed with schizophrenia or some other form of personality disorder.

This theory suggests that there may be an underlying a neurochemical component related to cannibalistic behavior. Many cannibals, such as Andrei Chikatilo, Albert Fish, Edward Gein, and Issei Sagawa, had been diagnosed with schizophrenia. Schizophrenia is defined in Reber's Dictionary of Psychology as a "general label for a number of psychotic disorders with various cognitive, emotional and behavioral manifestationsreflecting a cleavage or dissociation between functions of feeling and emotion" as well as a dissociation between thinking and cognition.