Technical issues simply require an answer, direction, or application of resources to solve a problem, which many leaders do in expediency to address conflict given the constant demands and issues they confront daily. On the other hand, wicked problems or adaptive challenges in organizations that confront managers are unstructured, and not only is it difficult to predict the outcomes of possible solutions with precision, but the ideal set of alternatives that should be considered before making a strategic choice is also often unclear. Most aspects of organizational life and change theory are based on assumptions of rationality as in normal science and its linear epistemology. The dominance of rationality in organizations results in ‘functional stupidity.’ Managers do not exhibit Functional Stupidity merely because they lack intelligence, expertise, or the right motivations/incentives. Most often than not technical solutions are used in decision-making for adaptive challenges (Kahneman, Lovallo, & Sibony, 2011). In cases where wicked problems are recognized and also acknowledged that technical solutions would only address the symptoms, managers still exhibit Functional Stupidity because they encounter systematic traps that impair their judgment. These cognitive biases are rooted in nature and are artifacts of wicked problems and adaptive challenges. Key cognitive biases include the confirmation bias, the sunk cost trap, the anchoring bias, and the framing bias. How can organizational leaders avoid these decision traps in addressing wicked problems? How can decision making on complex systems – the so-called wicked problems or adaptive challenges - come to grips with irreducible, or deep, un-certainty without cognitive biases? This paper discusses, complex adaptive decision making (messy solutions) in the context of four main cognitive biases: Confirmation Bias, Sunk Cost Trap, Anchoring Bias, and Framing Bias, and how to avoid functional stupidity in addressing wicked problems.