Response bias is a component of decision making that can be defined as the general willingness to respond a certain way. For example, in recognition memory, one can have a response bias towards responding that a test item has been previously studied, or in reasoning, one can have a response bias towards responding that a conclusion is logically valid. However, not all individuals have the same response bias. Indeed, there is some evidence that response bias is a stable cognitive trait in memory that differs across individuals (Kantner & Lindsay, 2012, 2014). One predictor of this trait may be cognitive ability, since it appears to predict response bias in memory (Zhu et al., 2010) and in reasoning (e.g., Handley & Trippas, 2015). While memory and reasoning have similar decision making components and may be very related (Heit & Hayes, 2011; Heit, Rotello, & Hayes, 2012), this experiment is the first to test whether cognitive ability predicts response bias in both tasks. Experiment 1 showed that higher cognitive ability participants were more conservative than lower cognitive ability participants in reasoning, but not in memory. Experiment 2 showed that participants did generally follow task demands to shift their bias some, but this shift was not predicted by cognitive ability. This study shows that further research is needed to examine individual differences in response bias as one way to account for what has previously been treated as noise.