Which word indicates a lack of restraint in decision-making?

The term "impulsive" indicates a lack of restraint in decision-making because it describes actions taken on sudden urges or desires without careful thought or consideration of the consequences. When someone makes decisions impulsively, they often act quickly and without deliberation, which can lead to hasty and potentially regretful outcomes. This contrasts with measured, cautious, and rational decision-making styles, which involve careful evaluation, forethought, and restraint. Thus, in the context of decision-making, "impulsive" accurately captures the essence of acting without proper control or deliberation.