Inappropriate behaviour is a sign Sign
In medicine a sign is what a physician finds by examining a patient. For example, a patient with the symptom of pain might have signs of a fast heart rate, a pale face, a clammy touch and tenderness. of executive dysfunction. Here is another way to think about it. The most primitive parts of our brains are concerned with survival: eating, movement, reproduction, elimination. The more advanced parts of our brains have learned how to over-ride these primitive parts, so that while still getting these jobs done, we can accommodate those base desires to behave well socially with one another. The highest forms of social behaviour are variants of the so-called golden rule - do for other people what you would like to have done for yourself, and don't do to anyone else something you would not like to have done to you.

The inhibitions that we usefully learn so that we can adapt our behaviours can become unlearned if we lose the capacity for inhibition, and so we act on our basic instincts. Much of the inappropriate behaviour of Alzheimer's disease Alzheimer's disease
A neurological disease that affects memory and behaviour. It is characterized by beta-amyloid plaques and neurofibrillary tangles in the brain. There is no known cause but genetics and lifestyle are thought to play a role. can be understood in this way.