We studied a simple binary prediction task and discovered that,when making predictions, humans display sequential effectssimilar to those in reaction time. Moreover, we found that thereare considerable individual differences in sequential effects inprediction, again similarly to reaction time studies. We discussour results in light of the view that sequential effects are thetrace of an attempt at detecting a pattern in the sequence, aswell as the possible influence of randomness perception in ourresults. We conclude that the same pattern detection mech-anism is likely to underlie sequential effects in reaction timeand prediction.