Well I can't really say how someone can be manipulated or the person being scammed.
The thing is we don't really know how it happens but we can manage to avoid it from happening.
Before someone is scammed that means the person is actually focused on one thing mostly which is money and gain in a short time or period.
So we fall into such because we are actually greedy seeking for quick money, so only of we can get that of our mind and focus we will be able to avoid being scammed.