Self-Serving bias
Etymology
A term from attribution research that crystallized in the 1970s; a 1975 review by Miller and Ross helped fix it. The word attribution itself is from Latin tribuere, "to assign" — the bias is a lopsided pattern in how we assign causes when the ego is on the line.
noun · /SELF-SUR-ving BY-us/
The tendency to credit your successes to yourself and blame your failures on circumstances.
What it names
The asymmetry in how we keep score of our own lives — wins prove our talent, losses prove the world was unfair.
Example
His post-mortem oozed self-serving bias: the good quarter was his strategy, the bad one was the market.
Related idea
Fundamental attribution error is about judging others — their failures are character, yours are circumstance. Self-serving bias is that leniency turned inward.