An overwhelming desire for harmony in a decision-making group increases the probability of

groupthink.

Explanation:

Groupthink: In social psychology, the term "groupthink" is described as a psychological phenomenon that generally occurs inside a specific group consisting of different people that possess the desire for conformity or harmony in that specific group and often results in a dysfunctional or an irrational decision-making outcome. The phenomenon of groupthink was proposed by Irving Janis in 1972.

In the question above, the given statement represents groupthink.