Answer:
a group-serving bias
Step-by-step explanation:
Group-serving bias: In psychology, the term "group-serving bias" is described as the human propensity to continuously attribute a specific group's successes towards the groups' own efforts, and therefore attributes failures to some outside interference. However, it can be seen in various ethnic groups, families, etc.
In the question above, Advik's belief illustrates a group-serving bias as he claims the won on the wisdom of the members of his groups.