Scout mindset refers to a trait which Julia Galef defines as "the motivation to see things as they are, not as you wish they were." Galef contrasts the scout mindset to the soldier mindset. Unlike scouts, who seek out evidence that improves the accuracy of their beliefs and treat being wrong as an opportunity to revise their model of the world, soldiers seek out evidence that confirms their existing beliefs and treat being wrong as a humiliating defeat.
In her book "The Scout Mindset: Why Some People See Things Clearly and Others Don't", Galef expands on the benefits of a scout mindset, and how to cultivate a scout mindset given that human motivations, social environments and identities often don't perfectly align with patient and deliberate truth-seeking. 
Galef, Julia (2021) The Scout Mindset: Why Some People See Things Clearly and Others Don’t, New York: Portfolio, p. ix.
Galef, The Scout Mindset, p. 14.
This topic's summary partially reuses bits from the summary of the Julia Galef topic without properly quoting it.