How we change what others think, feel, believe and do
This is our tendency to take credit for success (self-enhancing bias) and deny any responsibility for failure (self-protective bias).
This helps to protect our ego. It also enables us to confirm that we are meeting our goals.
We will tend to be less self-serving if other needs interrupt, for example if we are subject to public scrutiny.
Group-serving bias happens at group level, in the same way.
I am proud of my good exam results except for the failure in one subject where I was unfortunately rather ill on the day of the examination.
Set the other person up to succeed at something and then let them take credit. They will feel good and be more amenable to your requests. Or let them take the credit and then subtly blackmail them.
Be honest. Do not take credit when you do not deserve it. You will gain more credibility.