What drives violations of the independence axiom?

A vast experimental literature has documented violations of the independence axiom in choices under risk.
Several alternative theoretical decision models have been proposed to rationalize this robust evidence. One way to evaluate these models is to study their foundation in the psychology of decision-making. This paper proposes a laboratory experiment to investigate whether individuals violate the independence axiom when not confident about their preferences. Moreover, we study whether the descriptive power of the independence axiom increases when only nondegenerate lotteries over common outcomes are involved, as suggested by the literature. Finally, we explore the relationship among violations of the independence axiom, decision confidence, and risk aversion.