Final answer:
According to Freud, emotional disturbances can result from failures in specific stages of development that have lasting consequences in adulthood.
Step-by-step explanation:
According to Freud, failure to properly engage in or disengage from a specific stage results in emotional and psychological consequences throughout adulthood. For example, an adult with an oral fixation may indulge in overeating or binge drinking. An fixation may produce a neat freak, while a person stuck in the phallic stage may be promiscuous or emotionally immature. It is important to note that Freud's theories are not supported by empirical evidence, but they continue to be influential in various fields.