"For example, when freely choosing between the two options, people learned more quickly from the symbols associated with greater reward than those associated wi

"For example, when freely choosing between the two options, people learned more quickly from the symbols associated with greater reward than those associated with punishment, which removed points. Though that finding resembled a positivity bias, this interpretation was ruled out by trials that demonstrated participants could also learn from negative outcomes." So, a positivity bias implies that one cannot learn from negative outcomes? "But there was more to it. The experiments also included “forced choice” trials in which the computer told participants which option to select. Here, though the subjects still pressed keys to make the instructed choices, confirmation bias disappeared, with both positive and negative outcomes weighted equally during learning." Yes, confirmation bias disappears when it's not your decision that is being confirmed.