and Thomas Schultze (2010)

Die Übernutzung nicht valider Ratschläge: Warum schlechte Ratschläge über Gebühr berücksichtigt werden

Advice utilization during judgment and decision-making is an integral part of everyday life. The most stable finding in the literature on advice taking is that judges tend to place too much weight on their own judgments and do not utilize advice as much as they objectively should. This phenomenon is termed underutilization of advice. However, the opposite extreme, namely overutilization of advice, has largely been ignored so far. This dissertation provides first evidence for judges' inability to fully discount useless advice. Whereas advice from supposedly competent advisors was integrated to a high degree, judges failed to completely discount advice from supposedly computer generated random numbers that were said to have no validity whatsoever. The presented data further show that the overutilization of non-valid advice can be explained by a misperception of validity on the one hand and a combination of positive hypothesis testing and selective activation of target-relevant knowledge on the other.