Answer: Ingroup bias
Explanation:
Ingroup bias is defined as the tendency in which a person tends to favor their own group and ignore other groups traits. Group members, traits and results of own group drags a person to favor their group instead of analyzing other group's performance.
According to the question,believe of Tina and Betty is based on ingroup bias due to which they think that their own groups have better members who are skilled at spelling.They are favoring their own group over other group .
