Can optimism blind us?

Absolutely.

From Eurekalert, via FuturePundit:

In a study published today in Nature Neuroscience, researchers at the Wellcome Trust Centre for Neuroimaging at UCL (University College London) show that people who are very optimistic about the outcome of events tend to learn only from information that reinforces their rose-tinted view of the world…

And:

The researchers found that people did, in fact, update their estimates based on the information given, but only if the information was better than expected. For example if they had predicted that their likelihood of suffering from cancer was 40%, but the average likelihood was 30%, they might adjust their estimate to 32%. If the information was worse than expected – for example, if they had estimated 10% – then they tended to adjust their estimate much less, as if ignoring the data.

 
Related posts:

Can positive thinking be a very bad thing?

Do we perceive negative people as smarter and more competent than positive people?

Do troubled relationships need more positivity — or the exact opposite?