Final answer:
The false statement about Reactive Attachment Disorder (RAD) is that it is characterized by disturbed social relatedness not caused by other mental disorders, while actually, RAD derives from a history of extremely poor caregiving.
Step-by-step explanation:
The statement that is not true with regard to the definition of Reactive Attachment Disorder (RAD) is that it's characterized by highly disturbed and inappropriate social relatedness not due to other mental disorders. Reactive Attachment Disorder results from grossly pathological caregiving, including extreme child abuse, severe neglect, or frequent changes in caregivers, leading to an inability to form a proper emotional attachment to others. This disorder is distinct from resistant attachment and other attachment styles described by Ainsworth and colleagues, such as secure, avoidant, and disorganized attachments where the behaviors exhibited towards caregivers are due to different care responses.